就【jiù】

就 can mean "only, just", like 只 but more spoken. Before a noun or pronoun, it singles that one out: everyone else did one thing, only this one did another.

Before the verb: a small amount

就 before the verb, with a number after it, says the amount is small: only once, only one.

就这些 is a set phrase: "that's all, nothing more".

Only, or as early as

With a time word before 就, it means "as early as" instead. 他八点就来了 is "he came as early as eight". With a number after the verb, it is "only": 他就来了一次, "he only came once". That other 就 has its own point.

Where it goes wrong

就 comes before the verb, not after it.

• × 我吃就一个 → 我就吃了一个
• × 我们班有就三个男生 → 我们班就三个男生