There are three ways to end a complete sentence:

A period which ends a statement sentence. (.)

An exclamation point which ends a sentence that shows excitement. (!)

A question mark which ends a sentence that asks a question. (?)

"Spot is a happy dog." is a statement and it ends with a period (.). 

There are three ways to end a complete sentence:

A period which ends a statement sentence. (.)

An exclamation point point which ends a sentence that shows excitement. (!)

A question mark which ends a sentence that asks a question. (?)

"Will you eat that?" is a question and it ends with a question mark (?). 

There are three ways to end a complete sentence:

A period which ends a statement sentence. (.)

An exclamation point which ends a sentence that shows excitement. (!)

A question mark which ends a sentence that asks a question. (?)

This sentence ends with a period. 

There are three ways to end a complete sentence:

A period which ends a statement sentence. (.)

An exclamation point which ends a sentence that shows excitement. (!)

A question mark which ends a sentence that asks a question. (?)

This sentence ends with a period. 

There are three ways to end a complete sentence:

A period which ends a statement sentence. (.)

An exclamation point which ends a sentence that shows excitement. (!)

A question mark which ends a sentence that asks a question. (?)

This sentence ends with a period. 

There are three ways to end a complete sentence:

A period which ends a statement sentence. (.)

An exclamation point which ends a sentence that shows excitement. (!)

A question mark which ends a sentence that asks a question. (?)

This sentence ends with a period.

There are three ways to end a complete sentence:

A period which ends a statement sentence. (.)

An exclamation point which ends a sentence that shows excitement. (!)

A question mark which ends a sentence that asks a question. (?)

This sentence ends with a question mark. 

There are three ways to end a complete sentence:

A period which ends a statement sentence. (.)

An exclamation point which ends a sentence that shows excitement. (!)

A question mark which ends a sentence that asks a question. (?)

This sentence ends with a question mark. 

There are three ways to end a complete sentence:

A period which ends a statement sentence. (.)

An exclamation point which ends a sentence that shows excitement. (!)

A question mark which ends a sentence that asks a question. (?)

This sentence ends with a question mark. 

There are three ways to end a complete sentence:

A period which ends a statement sentence. (.)

An exclamation point which ends a sentence that shows excitement. (!)

A question mark which ends a sentence that asks a question. (?)

This sentence ends with an explanation point.