Read this sentence fragment; the boat in the harbor.
this is a fragment because:

a. it contains only five words.
b. it is missing a verb.
c. it is missing a subject.
d. it is missing both a subject and a verb.

D.) It's missing a verb.

Explanation:

Saying the ''boat is in the harbor'' is just plain

and boring and not saying anything. What is the boat doing? If you say

''the boat is ducking at the the harbor'' then that would have been more  

acceptable.

the sentence does not violate the phrase structure second rule (introduced by noam chomsky) because noun phrases consist of a determiner such as a, the or every, and a noun. in the sentence, the noun phrase the cake includes a determiner (the) and a noun (cake).

on the other hand, the first rule indicates that a sentence encloses a noun phrase, followed by a verb phrase. the example sentence can be analysed as follows:

john (n) + ate (v) + the (det) + cake (n).

c) vampires in history and modern life.