Verb complement or adverb of pupose?

hello everyone, am to ask bout the verb influence.In this sentence, ''I managed to influence him to forget about her remorse about her past. Is the infinitive to forget an adverb of purpose or just a complement, which could have been constructed this way '' i influenced the fact that he should forget'', but was not so, as the other one is more preferred.in the case of want, some mistakenly use it with a that clause, so i once heard some teacher say i want that you finish your assignment, though i know it is not right. from this sort of compliment error, i infer that the word influence may be used, although wrong, in the manner i mentioned above, am i right? sorry for the long sentences..hope to receive answers