There is no difference between plural and singular for most words. If I recall correctly, only words referring to people take a different form for plural.
Hi my comment is not exactly regarding this particular sentence, but more the food section overall, hope that is OK. I am finding I am repeatedly unable to complete part 3 of the food section because my keyboard has only some of the special characters required. For example the word corn - I have this á and I have this ą but not the special character which has the marks both above and below, therefore sadly my attempts at answering are always wrong. Can anyone who writes the course please suggest what to do. Other than being stuck so far I am enjoying learning your language. Whilst here I may as well also ask - one day you would consider adding audio, lol I can't be the only one with the atrocious pronunciation. (English doesn't have special characters) Thanks
If you're doing it on a computer, duolingo has buttons of all the unusual characters you can click on when you need them. That's how I've been doing it.
tłʼ is a single sound that is difficult to describe. Once I read that it's somewhat like an explosion from the sides of your mouth. I believe the tongue is in the same position it would be in if you were to say L.
I can't find an example of tłʼoh itself, but here are some tłʼ words: https://navajowotd.com/?s=tł
If you click on the individual words they have sound.