"A whole month?"
How do you know this is a question if you don't hear the question mark in spoken Irish (or so I read)? Shouldn't there be a question particle there somewhere?
If a difference in intonation isn’t heard, then one wouldn’t know if it were a question or a statement without further context. (Both an interrogative particle and a verb should be present to form a complete question.)
Sorry, but I'm still not clear on this: is it OK to make a question without an interrogative particle, depending on intonation alone?
Somehow an mí go léir? for "the whole month?" feels OK, but mí go léir? for "a whole month?" doesn't, but I can't quite explain why that is.
I'd put in in the same category as go léir - in fact, it's easier to read An lá ar fad as "all day long" - bhí mé ag freagairt an fhóin an lá ar fad - "I was answering the phone all day long" or "I was answering the phone the whole day", but iomlán has a slightly different meaning - it really does refer to the complete unit (whether it's mí iomlán or sicín iomlán).
Is not iomlan used as an adjective in this instance; suggesting iomlan mi as a correct solution?
In most cases, adjectives come after nouns in Irish (cailín deas, bosca mór, cáca milis), so when iomlán is used as an adjective, as in this sentence, you get Mí iomlán.