Why 言うから instead of 言ったから?

Question

これも結局 理沙が言うから 買っちゃったんだよね

I only bought this because Risa talked me into it.

Why is it not using the past tense: 理沙が言ったから ?　Not only was Risa saying this in the past, but even the resulting action occurred in the past.

Answer 1

言う in form, in a subordinate/relative clause, shows that this action occurred at the same time as the main verb. The main verb happened in the past, so the speaking did too. But what seems clearer in the Japanese is that the speaking was happening as "I" was considering the purchase. 理沙が言ったから sounds like before I even got to the store (or wherever) Risa had already talked me into the purchase.

The sequence of tenses in Japanese works differently from that of English.