～た

～た is the plain past of a verb: "did". It is ました without the politeness, so it is what you say to friends and family and what plain-style writing uses. It is built exactly like the て-form, with た for て and だ for で.

Made from the て-form

If you know the て-form, swap て for た and で for だ: かいて書いて → かいた書いた, のんで飲んで → のんだ飲んだ, して → した. The exceptions carry over too, so 行く is いった行った. A godan verb that happens to end in る, like かえる帰る, takes った like any other godan verb.

• × 行いた → 行った
• × 帰た → 帰った

もう and まだ

With もう, た is "have already done", which English says with the present perfect. The negative answer is not the past negative but ていない: it still hasn't happened.

• × まだ食べなかった → まだ食べていない

Usage notes

These go beyond a past event.

Noticing something

た also marks the moment you notice something: what you were looking for is there, what you were waiting for has come.

The negative

The plain past negative is the ない-form with ない changed to なかった: たべなかった食べなかった, いかなかった行かなかった.