if; in case; if it is the case that; if it is true that
as for; on the topic of
if that's the case; if so; that being the case
if possible; if circumstances allow
行くなら早く行きなさい。
If you are going, go quickly.
日本語なら少し分かります。
If it is Japanese, I understand a little.
あなたがそう言うならそうだろう。
If you say so, it must be true.