Sentences: Complete and Incomplete Sentences

A Sentence - What is it and what makes it complete?

What is a sentence?  You might have been taught that, at a basic level, a complete sentence consists of a subject, verb and object.  However, this definition is too simplistic.

I (subject) go (verb or action word) to the market (objective of the action `go').

Therefore, in the simplest sense, it is correct to say in a sentence there is a subject, verb and object.

However, as Man is complex so is language.

I exist.

This is also a sentence, but there is no object; there is only the subject, `I', and the verb `exist'.  Therefore, it would be more instructive to think of a complete sentence as one that includes a complete thought.

A complete sentence is one that is able to convey one's thought completely.

Take a look at the following and ask yourself which of these include a complete thought and which don't.

Even though I studied hard.

I tried my best to persuade her.

The mighty waves thundered.

While the game was on.

Waiting at the sidelines.

The incomplete sentences are the following since they do not include complete thoughts:

Even though I studied hard.

While the game was on.

Waiting at the sidelines.

The use of `even though', `while' and `waiting' indicates that the writer has more information to disclose.

1. I studied hard but something contrary to what would normally happen took place. What was it? We are not told.  However, if we add that information, as shown in the next sentence, then the sentence will be complete since the `full' thought is offered to the reader.  Even though I studied hard, I failed in the exam.
2. Again, something happened `while the game was on'. Therefore, to complete the sentence, I could add: A man ran onto the pitch while the game was on.
3. We have no idea what to make of the `waiting at the sidelines'. Waiting is a gerund, that is, a word ending in `ing'.  If I were to convert the given example to the following: Waiting at the sidelines is a bad idea, then the `waiting at the sidelines' becomes a gerund phrase, that is, it becomes a noun - the subject of the verb `is'.

The remaining two, which are repeated below, are complete sentences since they complete the thoughts that need to be expressed.

I tried my best to persuade her.

The mighty waves thundered.