The plural form

[espen180]

Do Japanese nouns have a common plural form?

I want to say 'I am 17 years old', but I don't know the plural form of 'nen', so all I can say is

Watashi wa juunana nen desu. (Is this even the right way to say it?)

Arigatou gozaimasu.

[undrentide]

Do Japanese nouns have a common plural form?

I want to say 'I am 17 years old', but I don't know the plural form of 'nen', so all I can say is

Watashi wa juunana nen desu. (Is this even the right way to say it?)

Arigatou gozaimasu.

Generally there's no distinction between single and plural, with a few exception to emphasize there're more than one.

As for "year" and "years", "nen" is used for both cases.
To state your age, we use "sai" instead of "nen".
(Nen is used for duration of time, sai is used for age.)

Watashi wa juunana sai desu.
I'm 17 years old.
:-)