Prepositions that express movement toward something are to, on(to), and in(to).
The most common proposition of movement or direction is to, which indicates direction towards a goal.
When the goal is physical (ex: a destination, place, event, room in the house) “to” implies movement in that direction.
I am going to school. (destination)
When the goal is an action, or a thought, “to” identifies a verb. “To”, in this case is part of the infinitive and expresses purpose (in order to).
She took called her friend to ask her about the test. (in order to)
Both examples in one sentence:
|She and her friend are going to school to study.|
|(destination)||(in order to)|
ON (TO) / IN (TO)
Onto and into are prepositions of direction that are made up of prepositions of location (on and in) + to.
onto (on+to) signifies movement toward a surface
into (in+to) signifies movement toward the interior of a volume
Note: Compound prepositions are often optional because we often use the single preposition in or on to indicate direction.
Verbs expressing a stationary position take only “on” or “in” (this reflects the ordinary meanings of prepositions of location.
He sat on the chair.
My bike is in the garage.
My computer is on the couch.
Dinner is on the table.
With verbs of motion, onto can generally be replaced by on.
Some exceptions where on / onto can’t be used interchangeably:
The plane landed on the runway.
I placed the new vase on the table.
I hung the painting on the wall.
I spilled juice on the rug.
We’re renovating and adding a sunroom onto the house.
With verbs of motion, “into” and “in” are used interchangeably except when the preposition is (1) the last word or (2) occurs directly before an adverb.
Remember that into shows completion of an action, in shows the position of the object as a result of an action.
Daniel put the dishes into the sink. The dishes are in the sink.
Leon put his gym clothes into the washing machine. The laundry is in the washing machine.
Can your pour the pasta sauce into the pot? The garlic bread is in the oven.
The kids went into the library.
They went in. (not into)
What kind of trouble has she gotten herself into?
What sort of trouble is she in?
Note: “move in” is a phrasal verb, but “move into” is verb + preposition.
The army moved in and took control.
Let’s move into the living room after dessert.
Into, in to, onto and on to
In constructions where on is an adverb or a phrasal verb particle attached to a verb, it should not be joined with to to form the single word onto.
May I log on to your computer?
If it is an adverb it will be able stand alone with its verb:
I tried to log on, but could not.