So I'm looking up "talamh" in the dictionary as I'm trying to make flash cards.

The Ó Dónaill 1977 on Teanglann tells me that it's both firinsneach and baininsneach, and gives different genitives for each (with "talun" being the feminine). All the other sources I see (the 1991 dictionary, tearma, etc.) just say masculine.

Can someone help me understand:

1. When do you use the masculine and when do you use the feminine forms of "talamh"?

2. Why isn't the feminine form mentioned in other sources?

3. Are there other words that work the same way?

4. Is there an underlying language concept here that I'm missing that would make perfect sense of all of this?

Go raibh maith agaibh!

In Old Irish talam was a masculine noun, of a declension which, in some forms, retained a final nasal consonant (acc./dat. sg. = talmain - gen. sg. = talman). This is why you still get forms like you've found in Ó Dónaill's gen. sg. talún.

I suspect the difficulty with such forms is that they were unstable as the language developed and speakers expected masculine nouns ending in a broad consonant to have a genitive form ending in a slender consonant, like the modern genitive talaimh. Some very common words like talam would have retained their original genitive forms, at least in regularly used terms and set phrases, while less common words would have lost their original endings and fallen in line with the emerging conjugation pattern.

The Old Irish word cú was of the same gender and declension, and also came to be treated as a feminine noun in the later language. You'll find that Ó Dónaill suggests that the genitive singular and plural, con is "used in certain phrases", even though in normal speech the expected genitive, cúnna, is generally used.

In the case of talam, it seems to have first started conjugating as a more typical masculine noun during the Early Modern Irish period, with the gen. sg. form an talaimh emerging as a new development. At the same time, the original morphological endings with the nasal consonant seem to have been reinterpreted as feminine, as gen. sg. forms like na talmhan also occur.

Unlike cú whose final nasal consonant became relegated to certain phrases in which it became fossilized by common usage, it seems that forms of talam with final nasal consonants were more resilient against standardisation throughout the development of the language, as there are certainly more examples in which it is still commonly used. Ó Dónaill gives plenty.

I suspect the feminine form isn't mentioned in other sources because it is not considered the "official standard" form. That is to say, it does not follow the grammatical rules set out in an caighdeán oifigiúil, meanwhile the masculine form does. Historically speaking, however, it the feminine forms are perfectly well justified. Perhaps some of the other speakers who use this form more frequently can comment whether it's still freely used in certain dialects?

Cúnna is plural (nom. & gen.), cú + suffix (a)nna

Genitive singular is cú (same as nominative)

Thanks, Labhrás, for catching that. I'd update my original post to fix, but it doesn't seem we have that option on older posts anymore.

Maybe it was only on the old forum we had that?