It was after he moved to Paris that he met other artists and began to try a new art form.

英语中为了强调句子的某一成分 ( 通常是主语、 宾语、 或状语 ) ， 常用强调句型： It is (was)+ 被强调部分 + that (who)... ； 被强调部分可以是主语、 宾语、 表语或状语； 强调的主语如果是人， that 和 who 都可用。 本句中强调的是时间“到巴黎以后”。 所以句子的正确形式为It was after he moved to Paris that he met other artists and began to try a new art form 。