A complete sentence must have at least one subject and one finite-verb. Finite verbs are forms like write, work, broke, was writing and would come. Their form changes with a change in the subject or tense. For example, the finite verb was writing will become is / am writing in the present tense and will be writing in the future tense. The exact form depends upon the number and person of the subject.
A sentence must contain at least one finite verb. Note that participles, infinitives and gerunds are non-finite verbs. They cannot make a sentence.
How many finite-verbs?
You can’t have more than one finite-verb in a clause. Note that you can have any number of finite verbs in a sentence, but their total number must equal the number of clauses in that sentence. If there are three clauses, there should be three subjects and three finite verbs.
Even if the verb is finite, it cannot be independent when it follows a conjunction. In other words, you can’t begin a sentence with a conjunction. There are quite a few exceptions to this rule and now beginning sentences with and and but have become sort of acceptable. Nonetheless, this is not something you should try while writing an important exam.
Clauses beginning with a conjunction
Any clause that begins with a conjunction must be attached to an independent clause. The following clauses cannot be sentences because they begin with conjunctions.
- Because he hadn’t made the payment.
- That smoking can cause cancer.
- For it will create jobs and revive the economy.
Sentence fragments are a common mistake found in ESL writing. Students often begin sentences with conjunctions without even bothering to check whether they can be attached to the previous sentence.
- Incorrect: His subscription was not renewed. Because he hadn’t made the payment.
- Correct: His subscription was not renewed because he hadn’t made the payment.
- Incorrect: I agree with the opinion. That smoking can cause cancer.
- Correct: I agree with the opinion that smoking can cause cancer.