how do you use 'for' in certain phrases like......
'thank you FOR the pint'
'thanks FOR the headache'
'thanks FOR thinking of me'
'you're welcome FOR the food'
you're welcome FOR that'

go raibh maith agaibh

I was expecting different kinds of sentences but all of the above are the same.

Go raibh maith agat as ucht an phointe.
Go raibh maith agat as ucht an tinnis chinn.
Go raibh maith agat as ucht smaoineamh orm.

Not sure about "welcome", but I'd hazard a guess at:

Go ndéana maith an bhia duit.
Go ndéana a mhaith sin duit.

quote:

Go ndéana maith an bhia duit.
Go ndéana a mhaith sin duit.

I think the underlying expression here is:

Go ndéana (sé) a mhaith duit.

Tá daoine ann a chreideann gurb ionann sé seo agus "Go ndéana Sé A mhaith duit" (.i. Dia). Níl a fhios agam. B'fhéidir go mbeidh a fhios ag Lughaidh, ós nath tuaisceartach é seo, mura bhfuil dul amú orm.

Pé scéal, ní dóigh liom gur minic a chloistear "you're welcome for X" i mBéarla ná i nGaeilge.

Is it only me, or somebody else feels that "You are welcome for the food" sounds strange? It is OK to thank FOR smth, but to WELCOME FOR sth????

The expression is "Go ndéana sé a mhaith duit" in both Mumha and Dún na nGall. Sé = it, .i. the thing you gave. "Let it be useful (of use) to you" is the translation. The pesky habit of saying "Fáilte romhat" in this situation comes from Conamara & learners.

>> The pesky habit of saying "Fáilte romhat" in this situation comes from Conamara & learners.

- Deir muintir Chonamara 'go ndéana sé ' mhaith duit' i gcás bia nó deoch a leagadh romhat is go nglacfá buíochas leis an mbronntóir. Is ionann é agus 'bon appetite'.

Is seanscéal agus meirg air an ceann seo. Féach: http://www.daltai.com/discus/messages/13510/13326.html

quote:

how do you use 'for' in certain phrases like......
'thank you FOR the pint'

Is the another way of thanking someone for something, along the lines of "Tá buiochas leat....pionta"(I forget the rest)?

Grma as an bpionta.

Go raibh maith agat as an bpionta.

Mostly just:

'togha fir, go raibh maith agat'
'maith an fear, go raibh maith agat'
srl.

'Go raibh míle maith agat'

The situation depends on the relationship of the buyer to yourself, be it man, woman, friend, new or old srl.