GRAMMAR DETAIL

と

when; whenever

Follows a nonpast clause to express a result that regularly occurs whenever a condition is met, as with a natural law or habit.

Examples

春になると川辺の桜が一斉に咲く。

When spring arrives, the cherry trees along the river all bloom at once.

このボタンを押すと、画面が明るくなる。

When you press this button, the screen gets brighter.

Structure: A nonpast plain predicate, such as a verb, takes と to introduce a condition.
Basic usage: このボタンを押すと、画面が明るくなる。 describes a set result that follows pressing a button.

Result and request
- 押すと画面が明るくなる explains how something operates. A condition leading to a request naturally uses たら, as in 着いたら電話してください.
Nouns and na-adjectives
- Nouns and na-adjectives retain だ, as in 休みだと and 静かだと. Do not remove it merely to match a verb construction such as 押すと.