if; when; after
when it comes to ...; as for ...; that ...
why don't you ...; why not ...; how about ...; what about ...
I tell you!; I said ...; I really mean ...
vocative particle
家に帰ったら電話します。
I will call when I get home.
時間があったら来てください。
Please come if you have time.
もし雨が降ったらどうする。
What will you do if it rains?