Grammar: と Conditionals

[Lance]

と is a particle that can mark the end of a conditional clause in certain cases. It is similar to たら. (note that と is a particle that can also be used for many other things as well, being used as a conditional is just one of its many uses)

The と conditional means two different things depending on whether the second clause is present or past tense.

If the second clause is in the present tense, a と conditional implies that the second clause is a natural consequence of the first clause.

For example,
まだ学生だと、あのバー入れません。
If you are still a student, you cannot enter that bar.

If the second clause is in the PAST tense, the と conditional is similar to the english "when." However, using と implies that the second clause happened unexpectedly.

図書館に返ると、三村さんがいた。
When I went to the library, Mr. Mimura was there.

The と conditional is utilized with the following rules.

First clause must be one of the following

1) Noun +　だ／でない
2) i-Adjectives(plain, nonpast)
3) na-adjectives + だ／でない
4) Verbs (plain, nonpast)

then we need a と and a comma

then clause 2.