既然

既然 ……，就……indicates a cause-effect relation. In the first clause, a fact that has happened or an idea that has been confirmed is mentioned; in the second clause, the conclusion, prediction, or suggestion is provided.

Attention:

The subject can be placed before or after 既然 in the first clause, while the subject should be placed before the adverb 就 in the second clause.

eg）

1)既然你不喜欢，(你)就别买了。

2)你既然不喜欢，(你)就别买了。

既然不喜欢，就你别买了。(X)