Identify the subject, verb, compliment, prepositional phrases and adjectives.

1. Your solution to this algebra problem is clever.
2. We felt full after we had eaten Thanksgiving dinner.
3. The setting of the story is a Spanish castle that looks old and deserted.
4. It is difficult to choose a winner when each contestant's costume looks elegant.

1. solution-sub, is-verb, clever-compliment, to this algebra problem-prep phrase
2. we-sub, felt-verb, full-compliment, after we had eaten-prep phrase, Thanksgiving-adj
3. setting-sub, is-verb, castle-compliment, of the story-prep phrase, , old, deserted-adj
4.it-sub, is-verb,, difficult-compliment, to choose-prep phrase, elegant-adj

2, After we had eaten is a clause, not a phrase. Phrases do not contain subjects and verbs.

4, To choose is an infinitive, not a prep phrase.

So #2 doesn't have a prep phrase.

And #4 doesn't have a prep phrase

Right. Neither has a prepositional phrase.

1. Subject: Your solution

Verb: is
Compliment: clever
Prepositional Phrase: to this algebra problem
Adjective: - (No adjectives in this sentence)

2. Subject: We
Verb: felt
Compliment: full
Prepositional Phrase: after we had eaten Thanksgiving dinner
Adjective: Thanksgiving

3. Subject: The setting
Verb: is
Compliment: a Spanish castle
Prepositional Phrase: of the story
Adjectives: old, deserted

4. Subject: It
Verb: is
Compliment: difficult
Prepositional Phrase: to choose a winner
Adjective: elegant