when doing sentence analysis there should always be a prepositional phrase, subject and the verb. the verb is the action and subject is the doer of the action. a prepositional phrase is the dog house rule, examples of the dog house rule are (of the dog house) (in the dog house) (beside or behind) ( on the dog house) the sentence you are using is a complete sentence because the prepositional phrase is (likes football) the verb is plays and the subject is peter. although the coma should come after the word and, also there is no need for the word himself it will only creat the sentence to be boring and it becomes a run on sentence the sentence should look like this: Peter likes football and, he also plays football. enjoy your english homework hopefully this helps.