つ
(Tsu)
general-purpose counter for small things (one, two, three…).
Connection rules
- +Japanese cardinal + つ (ひとつ, ふたつ, みっつ…). For 10, use とお (just the number, no つ).
- +Only goes from 1 to 10. For 11+ use 個 (こ) or another specific counter.
- +Useful for age when counting young children: ふたつ = 2 years old, or more generally via 歳/才 counter.
Examples
1.
りんごを三つください。

Ringo o mittsu kudasai.
Three apples, please.
「general-purpose counter for small things (one, two, three…)」
2.
質問が一つあります。

Shitsumon ga hitotsu ari masu.
I have one question.
「general-purpose counter for small things (one, two, three…)」
Practice
Please give me three oranges.
みかんを___。
Romaji also accepted