Which of these below are sentence fragments?
1. Several small shops went out of business.
2. The nurse pierced my arm four times with a syringe.
3. As it was her first airplane ride.
4. Because there was a gas leak.
5. The small child was always active.
You must know the definitions of sentences and fragments of sentences (sentence fragments) in order to answer this question. Fragments of sentences are missing a critical part of a complete thought. A complete thought is expressed by a complete sentence. Though there are some fine points to defining sentences that are not relevant to you now, a sentence must express a complete thought and have a Subject and a Predicate.
A Predicate is a tricky thing because it may encompass far more than just the required Verb in a complete sentence, which provides the action or state of being that is involved in the sentence. The Predicate encompasses any additional parts of the sentence because these additional parts are relevant to explaining what the Subject did or is, etc.
- The dancers / gave the Tango exhibition for the Queen at the Royal London Theatre.
This sentence has a complete thought, a Subject, and a Verbin a long Predicate. The Subject is "The dancers" and the Verb is "gave," while the Predicate is all that is associated with the Verb "gave": "gave the Tango Exhibition at the Royal London Theatre." The parts that follow the Verb answer the questions: "gave what to whom where?" These together comprise the Predicate.
If we wanted to, we might add another part that answers Why? or How? It would start with something like "because they thought ..." or "as they were ..." or "by contracting a new ...." It is these sorts of additions that are involved in your sentence fragment choices above. These sorts of additions are called embedded or subordinate or dependent adverbial clauses.
Look at option number 4: "Because there was a gas leak." This has a Subject: "there." It is serving as a relative pronoun introducing a relative clause. This also has a Verb: "was." It is followed by complementary noun phrase that answers "There was what?" that helps form the Predicate. Yet, this is a sentence fragment.
Why is this a sentence fragment while options 1, 2, and 5 are not fragments. This is a fragment because it is the answer to a larger question. It answers something like, "Why did the building tenants evacuate?" It answers, "They evacuated because there was a gas leak." The same sort of analysis holds true for option 3.
"As it was her first airplane ride," answers a larger question. It may answer "Why did the stewardess sit with her?" or "Why did the woman seem nervous?" or "Why did the grown woman bring her Teddy Bear??" We don't really know what option 3 answers because the information is missing: it does not express a complete thought even though it has a Subject and Verb ("it" and "was"). It is a fragment. If we take a guess at the missing information, we can complete the fragment: "Why did the young woman seem nervous? She seemed nervous as it was her first airplane ride."
The only two sentence fragments in your list are the two adverbial clauses, one beginning with the adverb "as" giving a reason for something unknown and the other beginning with the adverb "because" also giving a reason for something unknown.
1: complete sentence
2: complete sentence
5: complete sentence