This question came from a student of mine - he wanted to know how to parse the grammar of this sentence, which appears to be simple but clearly is not:
- Peter seems to have found his glasses.
Sentences of this form are very common in English but the syntax is puzzling. The main verb is clearly seems, usually a link verb, so the basic syntax ought to be:
Subject + Link Verb + Subject Complement S+LV+SC
But the verb phrase to have found appears to be tensed (present perfect), and the meaning delivered is similar to the the tensed form (he found them and they are still found). But this verb phrase can not be tensed and does not agree with the subject (if it did it would be has found). It has to be a verb complement.
Now, the rule for subject complements is generally that they are either an adjective phrase or a noun phrase, but this complement is neither, and yet it clearly is describing the subject.
So the question is - how do we parse this?
Other sentences with the same form follow:
- The answers given seem to have addressed your question adequately.
- I am lucky to have found this site.
- The library seems to have closed.
So, what is the best way to parse the grammar of sentences like these?