In this sentence and answer from the lesson, why is the first verb conjugated in the present tense?

Bonjour John, It's in the present tense because we know now, and have known since you told us. French has no equivalent for the present perfect "have known" - the present tense is used instead.

Bonjour John, Yes, indeed, like Laura said, we don't have an equivalent of that fascinating tense, the Present perfect, that seems to be sitting in-between past and present. So in French, you will use either Le Présent when the action is still ongoing now, OR Le Passé Composé when it occurred in the past. In this case, they still know at the time they're speaking, so Le Présent! Hope that's helpful!