What is a sentence?
A sentence is a group of words that expresses a complete thought; it is an independent clause (a group of words that can stand by itself) that contains a subject and a verb.
Example #1 (Sentence)

I feel very sluggish today.
Reasoning: This sentence contains a subject (I) and a verb (feel) in the main clause. It contains a complete thought that lets us know what is happening (someone feels very sluggish).

When is a group of words NOT a sentence?

A group of words is not a sentence when it is missing one or more of the following: a subject, a verb, a complete thought. We call this an incomplete sentence or a fragment.

Example #2 (Not a sentence.)

Very sluggish today.
Reasoning: This group of words does not contain a subject or a verb, and there is not a complete thought. To have a subject, we would have to ask: Who or what is very sluggish today? Also, we would have to add a verb such as is or feels in order for this group of words to make sense.


There are two ways to determine if a group of words is a complete sentence.

  1. If you can identify the subject, the verb, and a complete thought.
  2. Say the group of words out loud as if you are addressing someone and see if it makes sense. If it does not make sense, chances are good that it is not a complete sentence.

Example: If someone said to us: "Is very sluggish today," that would not make sense because we don't know WHO are WHAT might be sluggish today.

Exercise 1 | Exercise 2