vere

Vere is the regular adverb of verus, "true", formed the ordinary way for a first and second declension adjective. Its comparative is verius and its superlative verissime.

Three things to keep apart, because they all look alike in an unmacronised text. Vere is this adverb. Vero is a different adverb meaning "but in fact, however", a mild adversative that sits second word in its clause, and it is also the ablative of verum. And vere is equally the ablative of ver, veris, "spring", so vere in a poem may well be "in the springtime". Word order helps: the adverb tends to lead the clause or hug the word it strengthens, while the season wants a verb of time near it.