"I am seventeen years old."

Translation: 十七歳です。

[SkandarSan]

Is it always じゅうしち or can it be じゅうなな?

[Airichann]

According to my japanese mom, no one says じゅうしちさい everyone says じゅうななさい so I guess duolingos in the wrong here, but thats for age, the first is used for other things

[elementart_]

They seem to have fixed it now with the latest updates to audio

[Geo9955]

From my understanding of it, なな is said any time the number in question is above 10 (17, 27, etc.), and しち is used whenever you want to say 7 by itself.

So 七 would be しち, and 十七 would be じゆうなな. I think there's similar rules for the other numbers as well!

[joaopedrofn00]

Actually nana is used almost every time, only in some situations shichi is used, but in general no one says shichi, except when is needed.

[krizb]

Probably なな and よん are used when you do not want to attract bad luck (しち and し sound similar as しぬ = to die).

[joaopedrofn00]

yes, that is the reason to avoid shichi, but there are situations that you have to use it.

[AmaranthZi]

when I was in Japan I heard if you knock on someones door 4 times (knock knock knock knock) they won't answer because "shi"

[secret_sAndwich]

Duo is hit or miss with accepting kanji in answers (even though it's provided as a pop-up translation). Reported.

十七歳です。

[winterame]

Lolol, I wasn't careful and I typed that I was 70 七十

[tsuj1g1r1]

7 downvotes? You people take careful typing very seriously.

[denimbluesky]

歳 should be pronounced さい not とし in this use?
Duoļingo is wrong?
Anyway I reported the sound wrong

[rebeccakllr]

十七歳です　should be accepted.

[yzuzqWGo]

Duo doesn't accept じゅうななさいです