其实 + [clause]
[subject] + 其实 + [verb phrase]
其实 introduces what is really the case. It goes at the start of a clause or after the subject, before the verb.
The most common shape sets an appearance or a belief in the first clause, then corrects it with 其实. 看起来, 听起来 and 以为 often set it up.
At the start of a conversation turn, 其实 admits something the listener didn't know.
English "actually" can trail at the end of a sentence. 其实 can't.