I know how to say "I saw a cat" 「猫を見た」. However once a verb get's involved I'm not so sure anymore. I have two ideas on how to say it. The sentences is suppose to read "I saw someone being in that house over there".
I don't know if either of those sounds any good. How would you report seeing something that involves a verb? Rephrasing it without the verb is not allowed unless you have a way to do it with all verbs and nouns. Also if there exist a nuanced way of saying it that implies that what is being seen is still ongoing, please share that as well. Like I saw a person there and he is still there.