Well, I see what you mean, but adverbs of purpose express 'in order to', like this,
1a. Find someone who offered
to help. (OK; Object)
1b. Find someone who offered
in order to help. (Not OK; Adverb)
By the way, 'to help' is a phrase, an infinitive phrase, which means it lacks tense.

A clause has tense, as well as a subject. :wink: