Grammar Post

Well.. Something grammatical that i feel i struggle with is prepositions of to onto into
i think its hard to know which one goes for the right place so this website was quite helpful. (the website is shows pictures that really help demonstrate what each example of rule is)
1. The basic preposition of a direction is "to."
TO: signifies orientation toward a goal
When the goal is physical, such as a destination, "to" implies movement in the direction of the goal.
(1) Sa'id returned to his apartment.
When the goal is not a physical place, for instance, an action, "to" marks a verb; it is attached as an infinitive and expresses purpose. The preposition may occur alone or in the phrase in order.
(2) Li Ling washed her dog (in order) to rid it of fleas.
The two uses can also occur together in a single sentence:
2. The other two prepositions of direction are compounds formed by adding "to" to the corresponding prepositions of location.
The preposition of location determines the meaning of the preposition of direction.
ON + TO = onto: signifies movement toward a surface
IN + TO = into: signifies movement toward the interior of a volume
("To" is part of the directional preposition toward, and the two mean about the same thing.)
3. With many verbs of motion, "on" and "in" have a directional meaning and can be used along with "onto" and "into".
(See the sections below for some exceptions to this rule.) This is why "to" is inside parentheses in the title of the handout, showing that it is somewhat optional with the compound prepositions. Thus, the following sentences are roughly synonymous:
(4) Tai-shing jumped in/into the pool.
(5) Porfirio fell on/onto the floor.
(6) The crab washed up on/onto the shore.

To the extent that these pairs do differ, the compound preposition conveys the completion of an action, while the simple preposition points to the position of the subject as a result of that action. This distinction helps us understand how directional and locational prepositions are related: they stand in the relationship of cause and effect.
Completion of an Action

Position of Subject

(7) Jean fell on(to) the floor.
Jean is on the floor.
(8) Susumu dived in(to) the water.
Susumu is in the water.

Uses of "to"
To occurs with several classes of verbs.
1. verb + to + infinitive
Verbs in this group express willingness, desire, intention, or obligation.
willingness: be willing, consent, refuse
desire: desire, want, wish, like, ask, request, prefer
intention: intend, plan, prepare
obligation: be obligated, have, need
Examples:
(9) I refuse to allow you to intimidate me with your threats.(10) I'd like to ask her how long she's been skiing.(11) I plan to graduate this summer.(12) Henry had to pay his tuition at the Bursar's office.

Uses of "onto"
1. "Onto" can generally be replaced by "on" with verbs of motion.
http://owl.english.purdue.edu/handouts/esl/eslprep.html