Building complete sentences

The three-part test#

A complete sentence usually passes three checks:

1. It names or implies a subject.
2. It contains a finite verb that shows tense or agrees with the subject.
3. It expresses a complete thought.

“The workshop begins after lunch” passes all three checks. Workshop is the subject, begins is the verb, and the statement can stand alone.

Subjects can be understood#

Commands often have an understood subject rather than a written one.

• “Read the explanation again.”
• “Check your answer before continuing.”

The understood subject is you, so each command is a complete sentence.

Fragments with dependent words#

A group of words may contain a subject and a verb but still be incomplete. Words such as because, although, when, if, and while can make a clause dependent.

• Fragment: “Because the lesson begins at nine.”
• Complete: “We arrived early because the lesson begins at nine.”
• Complete: “Because the lesson begins at nine, we arrived early.”

The dependent clause needs an independent clause to complete the idea.

Fragments without a finite verb#

An -ing form does not always act as the main verb by itself.

• Fragment: “The students waiting near the door.”
• Complete: “The students are waiting near the door.”
• Complete: “The students waited near the door.”

Adding are creates a present continuous verb; changing waiting to waited creates a simple past verb.

Run-on sentences#

Two complete thoughts should not be joined with only a comma.

• Run-on: “The example was clear, I solved the next question.”
• Correct: “The example was clear, so I solved the next question.”
• Correct: “The example was clear. I solved the next question.”

Use a coordinating conjunction, a semicolon, or separate sentences according to the relationship between the ideas.

Common mistakes#

Trusting punctuation alone

“Because the lesson ended.” has a capital letter and a full stop, but it remains a fragment because the thought is incomplete.

Treating a long group of words as complete

Length does not determine completeness. “The carefully organised notes on the desk” is a noun phrase, not a complete sentence, because it has no finite verb.

Repair strategy#

Underline the subject once and the finite verb twice. Then ask, “What am I still waiting to learn?” If the words leave a question unanswered, add the missing independent clause or main verb.