What does だったら mean?
だったら is a Japanese conjunction meaning “in that case” in English. It is written as だったら in hiragana, and dattara in romaji. This word is part of JLPT N3 vocabulary.
Example sentences
疲れているの？だったら、少し休んだほうがいいよ。
Are you tired? In that case, you'd better have a rest.
雨が降りそう？だったら、傘を持っていこう。
Does it look like rain? In that case, let's take an umbrella.