Conjunctions are words, that connect partial clauses or just single words with one another in a relationship.

Im Irish (as in German) it is common that certain expressions are often used as "complex conjunctions".
Those expressions here portray just a selection of the rich array of such constructions.
Divided by their compositions, there are many types of conjunctions:

• simple conjunctions (consisting of one word), e.g. ach, agus, nó, ó, sula, including also:
  •  má, dá, mura that pull to a (real/irreal) conditional clause
  • Interrogatives as conjunctions cé, céard, cá, conas etc.
  • Interrogative verbal particles as conjunctions: an, ar, nach, etc.
• constructions, that contain agus (or abbrev.: is), less commonly ach, nó.
• constructions, that contain go/nach
  • the use of "agus go/nach" contains a description of condition
  • instead of a go- subordinating clause, often an infinitive construction is possible (e.g.  le hé an fear a bhualadh instead of le go mbualann sé an fear = so that he hits the man, equivalent to the German "um zu": le fear a bhualadh = in order to hit the man
• constructions, that contain a/nach (relative particle) and with that introduce a (direct/indirect) relative clause.
  • the use of "agus a/nach" contains a comparison

The division chosen here in coordinating and subordinating conjunctions has little meaning for the Irish, for except select conjunctions, the main and subordinating clauses do not differ in syntax. Especially, the word order does not change in the subordinating clause, as is common in German. Confusingly, one must add, that coordinating conjunctions in altered meaning alone or in compounds may introduce subordinating clauses.

Coordinating Conjunctions (cónaisc chomhordaitheacha)

Inclusive  conjunctions (cónaisc charnacha)

These contain a list, in which all connected parts are included.

and

and has two forms: agus (rather long for a so often used word) and is (short form, easily confused with the copula is!)
In old gaelic script there appears often as shorthand the tyronic notation 7 in its place (similar to a seven, that is here as a substitute).

examples:
Tá mé sásta inniu agus bhí mé sásta inné. = I am today and was yesterday satisfied.

In lists, one uses agus between each of the terms ("polysyndetic coordination")
In German and English and is mostly only between the last two terms ("(mono)syndetic coordination"):
e.g.: Pól agus Seán agus Séamas agus Dóirín a bhí ann.= Paul, John James and Doreen waren da.

Between adjectives, however, there is normally no agus ("asyndetic")
e.g.: an cailín óg álainn = the young and pretty girl
e.g.: Tá an aimsir te tirim = the weather is hot and dry.
(between the same comparitives use sa:
e.g.: measa sa mheasa = worse and worse)

other uses of agus

in affirmative answers:
Agus is in affirmative answers preceding supplementary information: e.g.:
An bhfuil cead agam tobac a chaitheamh? - Tá agus fáilte = May I smoke? - Yes, please do.
Ólfaidh mé fuisce. - Ólfaidh agus mise. = I will drink whiskey. - Yes, me too.

As part of other conjunctions
Agus, is is part of many other conjunctions, mostly together with the direct relative particle a or with go = that
(e.g.: chomh luath is a = as long as; is go = until)

Ennumeration in the conditional clause
Agus is used for ennumeration in conditional clauses (these then as an infintive construction), see there

in comparative clauses
In comparitive clauses, that contain an equivalence, agus means "so, as".
Agus appears then together with the direct relative clause (agus a)
This is especially the case chomh + adjective and following other expressions of equivalence like ionann, mar a chéile = "same", amhlaidh = "so" or oiread = "as much as":
e.g.:
Ní hionann sin agus a bhí sé = That is not the way it was.
chomh maith agus a rinne sé é = As good as he did it.
Fuair mé an oiread agus ba mhaith liom = I received as much as I wanted.

With is amhlaidh, agus means "and matter of fact"
Is amhlaidh a tháinig sé abhaile agus a shrón briste = So he came home, and matter of fact with a broken nose.

Also in a comparison of similar clauses, in which a consequence of the one is described in the other (e.g.: "so good, that ...") one uses agus, and then with a go/nach-subordinating clause (agus go/nach). (not to be confused with agus go/nach in non-comparitive clauses, in which it takes on the meaning of a description of condition.)
agus appears as well in clauses of an irreal comparison (e.g.: "as good as if..."), then with an irreal conditional clause (agus dá)
e.g.:
Tá sé chomh maith agus go bhfuil sé ann. = It is so good that he is here.
Tá sé chomh maith agus dá mbeadh sé ann. = It is as good as if he were here.

with infinitive constructions
Agus can, as in German, connect main clauses and has then a normal coordinative function ("and")
The 2nd partial clause may appear as a verbal noun- or. infinitive construction.
Then, agus has a rather subordinating meaning.
For negation, one uses (common in verbal noun constructions) gan.
 

In such infinitive constructions, a bheith = to be is normally omitted (in the examples, it is for clarification purposes in parentheses).
e.g.:
Chonaic tú an fear agus gan tú (a bheith) sásta. = You saw the man and were not satisfied
Agus é (a bheith) ag gáire, thit sé go talamh. = As he was laughing, he fell down.
Other verbal nouns can just as well be used, but are then of course not omitted.

Due ot the fact that an infinitive construction is used, this construction does not have the function of a main clause but rather of a subordinating clause. Agus has here different, more subordinating functions through the description of a certain condition, which stands in relation to the main clause.
Should the events of both clauses occur at the same time (recognisable through the usage of the progressive), one translates agus here to "while, as" : 
e.g.: Agus é (a bheith) ag gáire, thit sé go talamh = As he was laughing, he fell down. (lit.: "and he [to be] at laughing, fell he to the ground.")
The rather neutral description of condition may, depending on the context, ranging from "seeing as", "despite" to "even though" in translation. It can also take on the function of a modal attributive:
e.g.: D'imigh tú agus fearg (a bheith) ort = You left in anger (lit.: "Left you and anger (to be) on-you")
Instead of the infinitive construction, following agus a go-subordinating clause may follow, which makes the description of condition even clearer. (see also conditional conjunctions).

Similar constructions are also possible with ach = but , but then with a more restrictive (if it were not so, that; provided, that; ,etc.) or a conditional meaning (if)

not only but also

examples:
Bhí Pól chomh maith le Seán sásta = Paul, as well as Seán, were satisfied.
Idir mhná agus fhir a bhí sásta = Both men and women were satisfied.
Ní hamháin Pól a bhí sásta ach Seán freisin = Not only Paul but also Seán was satisfied.

neither nor

examples:
Ní raibh Pól ná Seán sásta = Neither Paul nor Seán were satisfied.
Ní íosfaidh mé agus ní ólfaidh mé = I would neither eat nor drink

In negative responses, ná helps in supplementary information:
e.g.: An raibh Pól ann? - Ní raibh ná Seán = Was Paul there? - No, and neither was Seán.

and not either, and even less so

With 2 negated statements, one can emphasize the negation of the second clause with agus ní mó = "and no more" or agus is lú = "and the least", followed by a dir. relative clause.

examples:
Ní raibh sé anseo agus ní mó a bhí sé ansin = He was not here and he was not there either.
Ní raibh sé sásta agus is lú a bhí mé sásta = He was not satisfied and I was even less so satisfied.

Exclusive conjunctions (cónaisc scaracha)

These contain a selection or a negative clause, that means a part of the statement will be excluded

or

example
An raibh Pól nó Seán sásta inniu = Were Paul or Seán satisfied today?

either or

examples:
Bhí Pól sásta é sin nó bhí Seán sásta = Either Paul or Seán were satisfied.

or else

examples:
Ith é nó neachtar acu íosfaidh mé é = Eat it, or else I will eat it.
 

Restrictive conjunctions (cónaisc chodarsnacha)

but, although

example
Tá mé sásta inniú ach ní raibh mé sásta inné. = I am satisfied today, but not yesterday.

other uses of ach

in negative responses
Ach is in negative responses preceding an eventual clause response or correction: e.g.:
An dochtúir é? - Ní hea, ach múinteoir. = Is he a doctor? - No, a teacher.

if
If the conditional is in the main clause, and the clause following ach is negated, then ach means mostly "if"
Thógfadh sibh an balla, ach níl clocha agaibh. = You would build a wall, if you had stones. (lit.: "... but you have no stones")

with infinitive constructions
Similar to agus, ach can introduce infinitive constructions (see for further info agus)
Then, ach has a subordinating function and a rather conditional meaning for "providing, that", "wenn" or a temporal meaning for "as soon as", "if", "as". e.g.:
Gheobhaidh tú é ach íoc as = You will get it when you pay for it
Tá sé maith go leor ach gan fearg a chur air = He is all right, provided the anger doesn't rise in him
Bhí sé sásta ach an leithscéal sin a ghabháil leis = He was satisfied, as soon as he got the apology.

instead of an infinitive construction also used together with the indirect relative particle a (ach a see as soon as)

only

except

Subordinating Conjunctions (cónaisc fho-ordaitheacha)

Complementary conjunctions (cónaisc ráiteasacha)

that /that not

examples:
Deir sé go bhfuil deifir air.= He said, that he's in a hurry.
Tá sé chomh fuar go bhfuil orainn ár gcótaí a chaitheamh. It is so cold, that we must wear our coats.
Deir sí nach bhfuil ceart agat. She said, that you aren't right.
Dúirt sí nár fhoghlaim sí a cuidse. = She said, that she hasn't learned her part.

In Munster, ná is used instead of nach (and ná go following a negative main clause):
Deir sé ná fuil sí ann = Deir sé nach bhfuil sí ann = He said, that she is not there.
Ní deirim ná go bhfuil sí ann = Ní deirim nach bhfuil sí ann = I don't say, that she isn't there.

Causal conjunctions (cónaisc chúise)

because / while

There is a vast amount of "becauses" and similar causal conjunctions.
 

others: óir, dóigh, ó (ós with the copula), arae, nó
These are in affirmative clauses mostly without go, in negative clauses however always with nach (like mar)

Some of these "becauses" allow a verbal noun construction (instead of go/nach-partial clauses)

examples:
Bhí faitíos roimpi mar go raibh sí an-ard. = One was afraid of her because she was very tall.
Rinne siad é mar nach raibh siad leisciúil. = They did it because they weren't lazy.
Bhí fearg air faoi go raibh siad ag déanamh gleo. = He was angry because they were making noise.
Ní dheachaidh mé go hÉirinn de bharr go raibh mé tinn. = I did not go to Ireland, because I was sick.
Óir is leatsa an ríocht agus an chumhacht agus an ghlóir. = For thine is the kingdom and the power and the glory. (from the Lord's Prayer)
Dóigh is liomsa é. = Because is is mine.
Ós í an Ghaeilge an teanga náisiúnta is í an phríomhtheanga oifigiuil í. = Because Irish is the national language, it is the first official language. (from: Art. 8 of the Irish Constitution)

Note that mar, that carries various meanings:
examples:
mar tá sé = because he is (mar + verb)
mar go bhfuil sé = because he is (mar + go-subordinating clause)
Compare with the other uses of mar:
mar a bhfuil sé = where he is (mar + indir. relative clause)
mar atá sé = how he is (mar + dir. relative clause)
The negative form mar nach is the same for all 3 uses, only the context gives the difference in meaning:
mar nach bhfuil sé = because/where/how he isn't.

that's why/ for / therefore / due to

examples
Níor tháinig sé agus sileadh mar sin gur mharbh a bhí sé = He didn't arrive and that's why one thought that he was dead.
Déanaim smaoineamh dá bhrí sin táim ann = I think therefore I am.
Is uime sin a dúirt mé leat é = That's why I'm telling you.

Circumstantial conjunctions (cónaisc imthoisceacha)

seeing, that (considering, that / depending on)

Circumstantial describe conditions under which other events occur. They remain relatively neutral with resepect to if the event due to or despite the condition (causal or concessive) takes place.
The describe only, that there is a connection between condition and event, that makes it necessary to view, consider and to describe an event.

others:
agus + verbal noun (the VN bheith is omitted)
agus + a + abstract noun + a + dir. relative clause   (see also abstract noun)
agus chomh + adjective + agus a + dir. relative clause

examples:
Ní haon ionadh sin agus gurb eisean do mhac = That is not surprising, seeing that he is your son.
Agus nach tusa a rinne ar chor ar bith é! = Considering, that you haven't even done it!
Ní dhéanfaidh tú é tráth agus nár thosaigh tú fós = You will not do it, since you have not even started with it.
Ní hionadh é agus a fheabhas a bhí tú = It is no surprise, as good as you were (seeing, how good you were)
Ní hionadh é agus chomh maith agus a bhí tú = It is no surprise, so good as you were.
Ba cheart duit a bheith amuigh agus an lá (a bheith) chomh breá sin = You should be outdoors, considering that the weather is so nice.

Concessive conjunctions (cónaisc fhaomhacha)

although/ despite / even if

instead of cé also gidh (gí)

examples:
Ní chreidim é cé go bhfeicim é. = I don't believe it, even though I see it.
Ní dhearna sé é, (d')ainneoin go dúirt mé leis é. = He didn't do it, although I told him to.
Níor tháinig fearg orm léi i ndiaidh nach n-éistfeadh sí liom. = I didn't become angry with her, even though she didn't want to listen to me.
Chuala mé iad siúd is nach bhfaca mé iad. = I heard her, although I didn't see her.
Má tá sé bocht féin tá sé fial. = Although ("even if") he is poor, he is generous
Fiú amháin tá sé bocht tá sé fial = Even though he is poor, he is generous
Fear leannta é, más ea féin, níl aon Bhéarla aige = He's a learned man, but he still can't speak English.

conditional clauses (má, dá) can possess a concessive character (also without féin), dá- clauses are then often with the indicative or imperative in the main clause (in the conditional meaning, the conditional is always in the main clause)

Final conjunctions (cónaisc aidhme)

with that/ so that/ so

d'fhonn is go is more accurately translated as "in the hope, that...".
ar eagla go means also more lit. "out of fear that"
Following sula (in Munster sara) the subjunctive is also allowed.

examples
Déan deifir le go mbeidh tú réidh in am. = Hurry so that you are ready in time.
Scríobh sí síos é ar nós nach ndéanfadh sí dearmad air. = She wrote it down, so that she would not forget it.
Chodail mé rófhada i riocht is go raibh mé déanach. = I overslept so, that I was late.
Dúirt sé é sin d'fhonn is go gcuirfeadh sé fearg orm. = He said that in the hope that it would anger me.
Tháinig sé anseo go bhfeicfeadh sé í. = He came here to see her.
Chuaigh sé abhaile sula bhfeictí é - He went home, in order not to be seen. (lit.: ... before he will be seen)

Temporal conjunctions (cónaisc ama)

until

Following these conjunctions, the subjunctive can be used, if it's concering indefinite time periods.

examples
Bhí siad ina dtost go dtí go bhfaca mé iad. = They were silent, until I saw them.
Fan nó go dtiocfaidh / dtaga sé. = Wait until he comes.
Ní thiocfaidh sé go bhfaighidh sé cuireadh uait. = He will not come, until you invite him.

since / since then

ó may also mean da (in the causal sense, similar to the engl. since) see because, for
with the copula, ó conjoins to ós
ó is also used as a preposition: ó = from, since.

example
Ní fhaca mé iad ó chuala mé an scéal. = I have not seen her, since I heard the news.

as soon as

Following ach a, the subjunctive tense is allowed, when it's about an indefinite time period.
Instead of the indir. relative particle a, an infinitive construction may follow ach (see ach)

examples
Glaofaidh sí chomh luath is a thiocfaidh sí abhaile. = She will call, as soon as she comes home.
Inseoidh mé sin dó ach a bhfeicfidh / bhfeice mé é.= I will tell him that, as soon as I see him.

before

sula / sular is a combination of sul ( = before) and the indirect relative particle a / ar, hence sul a/ar is also possible.
Regional: instead of sula also sara / sarar (Munster), sol (with dir. relative clause), sola, sul má (Connemara), roimh (Mayo)
Following sula, the subjunctive may be used (by indefinite time points/time periods)
Sula has also the final meaning "in order to not / to not".

examples
Béidh sé anseo sula dtaga mé ar ais. = He will be here, before I return.
Béidh sé anseo sara dtiocfaidh mé ar ais. = He will be here, before I return.
Bhí siad ina suí sara ndéaradh sé focal - They stood up, before he could say a word.
Phéinteáil sé an doras sular tháinig Pádraig.= He had painted the door, before Pádraig arrived.
An t-am ar tháinig sé, bhíodar díolta ar fad.= Until (before) he arrived, they were all sold out.'
Roimh imeacht dom, béidh sé anseo = before I go, he will be here.

while, as (synchronicity)

chomh fada is a > chúns a (in Connacht)
More about le linn and ag + do + subject see here usage of the verbal noun: synchronicity

examples:
Bhí sé ag caoineadh an t-achar a / fad a / chúns a bhí sé ag caint liom.= He was crying as he spoke with me.
Le linn a bheith anseo dó rinne sé a chuid den obair = As he was here, he did his work
Agus é ag gáire, thit sé go talamh = While laughing, he fell over.
Ag léamh litreach dó fuair sé bás. = As he was reading the letter, he died.

as long as

example:
Tig leat é a choinneáil fad is a thugann tú aire dó.= You may hold it, as long as you take care of it.'

after

ar with the possessive pronomen a comprises the combined form arna

example:
Tiocfaidh an bhean tar éis imeacht don fhear. = The woman will come, after the man is gone
Ar chloisteáil na nuachta dí bhí sí tinn. = After she heard the news, she was sick.
Arna cloisteáil sin dí bhí sí tinn. = After she had heard it, she was sick.

when (temp.) / as

*  nuair < an uair = the time

examples:
Nuair a bhí mé óg, bhí mé i mo chónaí i nDún na nGall. = As I was young, I lived in Donegal.
Leag thart é nuair a bheidh tú réidh leis. = Put it away, when you are done with it.
 

every time, when

dá is here the combination of the preposition de and the generalising relative pronoun a. Dá appears often after gach + noun.

examples:
Gach uair dá bhfaca mé é, ní raibh sé ag obair. = Every time that I saw him, he was not working.

Conditional conjunctions (cónaisc choinníollacha)

if (condit.) / falls

In Irish, there are two types of conditions (conditional -)clauses, depending on if the realisation of the condition is possible (real conditional clauses) or just assumed (irreal conditional clauses).

Regional instead of mura / murar also muna / munar, mara / marar

Following má, any tense is allowed (instead of the future, the habitual present)
Following dá, normally comes the conditional or subjunctive-preterite (same form as the imperfect)
Following a realistic mura, any tense is allowed, also the subjunctive-present (in the future sense)
Following an irrealistic mura, comes either the conditional or subjunctive-preterite.

examples:
Má bhíonn sé sásta, tiocfaidh na fir. = If he is satisfied, the men will come.
Tiocfaidh fearg uirthi, mura ndéanfar di é = She will be angry, if one doesn't do it for her,
Murar chaill sí é, ghoid sé é. = If she hasn't lost it, he stole it.
Dá mbeadh lá maith ann dhéanfainn é. = If it were a nice day, I would do it.
Mura rachainn leis ní fheicfinn an mhaighdean mhara. = If I hadn't gone with him, I wouldn't have seen the mermaid.

for, if

mar dá:
Mar dá mbeadh sé ann bheadh sé sásta = For if he were there, he would be satisfied.

if it weren't so, (that)

This is used to describe results, if already realised conditions would not exist.
The main clause is in the conditional .
The subordinate clause follwing murach / ach is in the indicative.
Instead of a subordinate clause, an infinitive construction or a noun may also be written, in the latter case, murach becomes a preposition in the sense of "without".

example:
Ní chréidfinn é murach go bhfaca mé féin é= I wouldn't have believed it, had I not seen it myself.
Murach an balla = If it weren't for the wall, without the wall
Ach go bhfuil balla ann = If the wall weren't there.
Ach nach bhfuil balla ann = If it weren't so, that there was no wall (= if there were a wall)

provided, that

example:
Éireoidh leis an bhfiontar i gcleithiúnas go mbeidh cách páirteach ann.= The project will be a success, provided that we all participate.
Tig leat é a bhriseadh ar chuntar go n-íocfaidh tú as.= You may break it, if you pay for it.

also ach can be used in this sense (with verbal noun or with go; see also but)

if

In Connacht also má in the sense of "if " is used.
an / nach is a verb particle (here used in the sense of an"indirect query")

example:
Níl mé cinnte an bhfuil mé sásta. = I am not sure, if I am satisfied.
Ní mé ar chuala sé é. = I wonder, if he heard it.
Níl a fhios agam má tá Gaeilge aige. = I don't know, if he can speak Irish.

if ... or if (not)

e.g.:
Níl a fhios agam an bhfuil mé sásta nó nach bhfuil = I don't know, if I am satisfied, or not.
Níl a fhios agam cé acu atá mé sásta nó nach bhfuil = I don't know, if I am satisfied, or not.
Níl a fhios agam cé acu an bhfuil mé sásta nó nach bhfuil = I don't know, if I am satisfied, or not.
Bíodh sé sásta nó ná bíodh = if he is satisfied or not.

Instead of the negative nó nach (or not) another (positive) alternative with nó an, nó a (or if ) may also follow.
e.g.:
Níl a fhios agam an bhfuil mé sásta nó an bhfuil mé míshásta = I don't know, if I am satisfied or if I am unsatisfied.
Níl a fhios agam cé acu a bhí mé sásta nó a bhí mé míshásta = I don't know, if I was satisfied or if I was unsatisfied.

Of course there can be two alternatives in one clause (connected via nó = or).
e.g.:
An bhfuil mise nó tusa sásta = if I or you are satisfied
Cé acu mise nó tusa atá sásta = if I or you are satisfied

Pé, cé acu, cibé acu, an also with 2 adjectives directly following one another (without nó), also similar más with 2 adjectives:
e.g.:
Pé maith olc é = if it is good or bad
Más maith olc é = if it is good or bad
Más fíor bréag é = if it is true or false

The forms an, cé acu appear in indirect queries.
But pé, pé acu, cibé acu appear in the sense of a condition (to describe the ambivalence of the condition). In this sense the imperative form is used (sim. in German: "Sei es oder sei es nicht"=May it be so or not)

examples:
In the sense of an indirect query:
Níl mé cinnte an bhfuil mé sásta inniu nó nach bhfuil. = I am not sure if I am satisfied today or not.
Abair liom cé acu a bheidh tú ann nó nach mbeidh = Tell me if you will be there or not.
Níl a fhios agam an fíor bréag é = I don't know if it is true or false.

In the sense of an ambivalent condition :
Cibé acu a bheidh sé ann nó nach mbeidh, beimid sásta. = if he will be there or not, we will be satisfied.
Pé maith olc é = if it is good or bad, either good or bad, be it good or bad.
Pé maith olc leat é = either you like it or not, if you like it or not.
Beimid ann, tagadh sé nó ná tagadh. = We will be there, if he comes or not.

Ambivalence (neamhchúis) can also be expressed with dá + abstract noun in the sense of "how ... ever": dá olcas é = however bad, or with cibé in the sense of "who/which/what ever": cibé áit ar bith = whichever place/wherever

Modal conjunctions (cónaisc mhódúla)

as if

After mar a, etc. follows mostly a verb in the conditional.
mar dhea go has the meaning of an intentional faking (similar also the verb lig (ar ... go) (engl. to let on = to pretend): "to do so, as if "
(mar dhea originally mar bh'ea, lit. "as were it")

examples:
Chorraigh sí ar nós dá mbeadh sí ag iarraid í féin a bhaint as poll.= She moved around, as if she were trying to free herself out of a hole.
Níor chuala mé aon rud ach oiread agus dá mbeadh gan duine a bheith beo sa bhaile seo. = I heard nothing, as if no one in this village were alive.
Bhog sé a cheann (ar nós) mar a bheadh sé ag seinm.= He moved his head (so), as if he were playing music.'
Bhí an múinteoir go maith dom fearacht dá mba mé a mhac féin = The teacher was so good to me, as if I were his own son.
Bhí an múinteoir go maith dom i leith is gur mé a mhac féin. = The teacher was so good to me, as if I were his own son.
Bhí an múinteoir chomh maith dom is dá mba mé a mhac féin. = idem.
D'fhan sé ansin ag ligean air féin gur ag breathnú ar an teilifis a bhí sé = He stayed there and did so, as if he were watching television.

like, as

sa chaoi a in Connemara also sa gcaoi a;  also without article: i gcaoi a

examples:
D'fhág sí é sa gcaoi a raibh sé. = She left it as it was.
Seinneadh port ansin, mar a rinneadh go minic. = Then a melody was played, like one had often done it.
Amhail a dúirt sé = Exactly, as he said.

see also about the comparitive under comparitive conjunctions (so ... like, (more) than)

as much(...) as

example:
Níl oiread airgid agam agus a cheapfá. = I haven't as much money, as you think.

as far as

example:
Níl sé anseo ar feadh a bhfuil a fhios agam = He is not here, as far as I know.
 
 

Local conjunctions (cónaisc áite)

where

* mar a  can also mean "where" (with an indirect relative clause) or "how" (with direct relative clause):
Bíodh sé mar atá sé agus Trá Lí mar a bhfuil sí = May it be, as it be and may Tralee be, where it may be (saying)

example:
Lorg iad mar ar chuir tú iad.= Look for them (there), where you left them.
Fan san áit a bhfuil tú.= Stay where you are!
Níl a fhios agam cá bhfuil tú = I don't know, where you are.