Fòram na Gàidhlig

Tha mi a' thoirt seachad fada cus a tide le mo Ghaidlig, agus 's dochas feumaidh mi seo a dh'aithghearr!

While "Tha i air ga fhagail" (she is after at his leaving) feels good on the tongue it doesn't make a lot of sense. However while my other idea - "tha i air fhagail" (she is after his leaving) - makes more sense in English it seems very short of information content in Gaidhlig.

Can anybody help straighten me out here?

Le meas, MJ

Tha i air ga fhàgail

This is not grammatical.

tha i air fhàgail

This is. But note that English has a preference for tortuous passive and passive-ish constructions. Gaelic is the other way round, if there is nothing specifically passive about a situation, Gaelic prefers to switch subjects and use the active voice instead.

So for example instead of "you have been seen", which is totally natural in English, I would guesstimate that in native Gaelic, 9 times out of 10, people would go for "you were seen" (chunnacas thu) or, if the subject is known, chunnaic e/i/iad/daoine thu. In your example, the most likely utterance in this situation would be dh'fhàg i e (or thrèig, if it's more like abandoning).

Ahha - seachd uairean nas fhearr. Tapadh leat

You can use "Tha i air fhàgail" if you want to express that she just left him, or already left him.

Tha mi air ithe - I have finished eating