[Facts] Valerie and Valentina
Why aren't they from the same root if they both mean strong and have similar starts?
Replies
They do share the same root: the Latin verb 'valeo' meaning "to be strong/healthy". The difference is that Valerie comes from the present infinitive form, 'valere', and Valentina comes from the present active participle, 'valens'.
I think the suffixes on them also serve different purposes, but I don't know enough about Latin to be sure about which does what. Valentina has Valentine, Valerie has Valeria, Valerian, and Valerius. I imagine to Romans (and anyone else that spoke Latin at the time) those probably had different purposes and contexts they'd be used in (unless one of those variants is too new to have been spoken in Latin)