TWO-WORD VERBS

Many prepositions in English may combine with verbs to change the meaning of the verb. For example, compare the verbs to pull (to drag), to pull off (to accomplish), and to pull out (to leave). Don’t confuse a compound verb with a prepositional phrase.

Examples: He turned into a monster. (Turned into means became.)
The van turned into the driveway. (Into the driveway tells where he turned.)
He ran up a gigantic bar tab. (Ran up means a ccumulated.)
He ran up the hill. (Up the hill tells where he ran.)

SPECIAL USE OF ‘TO’
Another word that causes confusion is the word to. To is a preposition (“We went to the store”). However, to is also the first word of an infinitive, such as to eat, to run, etc. Remember that when to precedes a noun phrase, it functions as a preposition. When it precedes a verb, it is part of an infinitive.

Examples: Bob went to the store. (To the store tells where he went.)
Bob loves to surf. (To surf tells us what Bob loves.)

PREPOSITION OR CONJUNCTION?
It is sometimes easy to confuse prepositions with conjunctions. If the word is followed by a clause -- which is a unit of words that contains a subject and a verb -- it is a conjunction. If the word is followed by a simple noun phrase, it is a preposition.

Examples: Be home before midnight. (before is a preposition)
Be home before the clock strikes midnight. (before is a conjunction)
The President appeared before the full Senate. (before is a preposition which leads the prepositional phrase “before the full senate”)