What is a Sentence? (4 Types of Sentences)

It may astound you to realize that every thought you've ever communicated was a sentence. In fact, all thoughts you think are basically sentences.

What's fascinating is, given the ubiquity of the sentence, you would suspect most would have no problem defining it.

Nevertheless, my suspicion is that most would find it difficult to offer a concise explanation of the word, if pressed.

How to form sentences

Sentences are a set or series of words that include:

Subject: What the sentence is about — the sentence topic (either a noun or a pronoun).
Predicate: Says what the subject is doing or its current state (contains the sentence verb, along with any sentence objects or modifiers).

Subjects do or perform the sentence action, otherwise they receive it. Predicates are what we mean by the "action"—they communicate what's happening with the subject (whether a it's a literal action or a state of being).

Try to identify which words are the subject and predicates in the following sentences:

What are the types of sentences?

We classify sentences by 2 metrics—function and structure. These categories are not mutually exclusive; i.e., an interrogative sentence may also be complex, and so forth. The 4 types of sentence structures are:

Comprises both an independent and dependent clauses conjoined by a subordinating conjunction.

4 types of sentences by function

Declarative sentences make a statement or assert something—they provide information. They're the most common type of sentence and can express facts, opinions, observations, or ideas. We use declaratives in both affirmative and negative forms; they also vary in length and complexity.

Interrogatives are question sentences that end with a question mark (?): they often start with question words (who, what, where, when, why), auxiliaries (is, are, was, were, had, have), or modals (should, would, etc.) The job of interrogatives is to gain information or clarification.

Imperatives give commands, instructions, or make requests. The subject (you) is often implied rather than stated; tone can be polite or forceful depending on wording.

Imperatives either end in a period or an exclamation mark, and uses the simple present tense as its main verb form.

Sentences that express strong feeling or emotion; they often end with an exclamation mark and may use exclamatory structure to emphasize emotion.

Worksheet: Types of sentences

Practice identifying the correct sentence type for each sentence according to its function.