to

preposition

1》 expressing direction or position in relation to a location, point, or condition.

    ↘chiefly Brit. (in telling the time) before (the hour specified).

2》 identifying the person or thing affected.

3》 identifying a relationship between one person or thing and another.

    ↘indicating a rate of return: ten miles to the gallon.

4》 indicating that two things are attached.

5》 governing a phrase expressing someone's reaction: to her astonishment, he smiled.

6》 used to introduce the second element in a comparison.

7》 placed before a debit entry in accounting.

infinitive marker

1》 used with the base form of a verb to indicate that the verb is in the infinitive.

    ↘(about to) forming a future tense with reference to the immediate future.

2》 used without a verb following when the missing verb is clearly understood: she said she didn't want to.

adverb so as to be closed or nearly closed.

Origin

OE tō (adverb and preposition), of W. Gmc origin.