"I will be drinking on Saturday."
Translation:Bidh mi ag òl Disathairne.
Bidh is the positive statement form - bidh mi ag ithe marag-dhubh feasgar an-diugh.
Cha bhi is the negative statement form - cha bhi mi ag ithe marag-dhubh idir.
Am bi and nach bi are the positive and negative question forms - am bi thu ag ithe marag-dhubh? Nach bi thu ag ithe marag-dhubh?
It's easiest to remember the forms with their particles, rather than on their own - bidh, cha bhi, am bi?, nach bi?
In general verbs in Gaelic have two sets of endings (and sometimes entirely different forms).
The first one is independent (when the verb stands on its own, or in some relative sentences) – this is the positive form, mostly used for positive statements. Independet forms of bi are: tha in present, bidh in future, bha in past. For example:
- tha an cat ann – the cat is there (positive statement)
- dè (a) bha ann an taigh? – what was in a house?, lit. what-is-it that was in a house? (direct relative clause),
- bidh mi ag òl – I will be drinking (positive statement)
The second one is dependent – that is a form used after some particles (like negative cha(n), interrogative a/an/am, negative-interrogative nach, the particle gu ‘that’ introducing indirect speech, and in some relative clauses). Dependent forms of bi are (bh)eil in present, bi in future, robh in past. For example:
- a bheil an cat ann? – is the cat there? (after an interrogative particle)
- chan eil cat ann – there is no cat there (after negative particle)
- an duine ris an robh i a’ bruidhinn – the man with whom she was speaking (indirect relative)
- cha bhi mi ag òl – I will not be drinking (after negative particle)
But then there is also a third form in the future tense, the relative form, used in relative clauses, it ends in -s:
- an duine a bhuaileas e – the man that he will hit (or: the man that will hit him)