Prepositions "On", "At", and "In"

A preposition is a word that links a noun, pronoun, or noun phrase to some other part of the sentence.

Prepositions can be tricky for English learners. There is no definite rule or formula for choosing a preposition. In the beginning stage of learning the language, you should try to identify a preposition when reading or listening in English and recognize its usage. 

• to the office
• at the desk
• on the table
• in an hour
• about myself

A preposition is used to show direction, location, or time, or to introduce an object. 

Auxiliary Verbs "Can/Could" and "May/Might/Must"

Can

Used to express ability (to be able to do something):

• I can make jewelry.
• He can’t speak French.
• Can you open this jar?

Used to ask for permission:

• Can I use your bathroom?
• Can I leave now?
• Can I raise the volume?

Auxiliary Verbs "Will/Would" and "Shall/Should"

The verbs will, would, shall, should, can, could, may, might, and must cannot be the main (full) verbs alone. They are used as auxiliary verbs only and always need a main verb to follow. 

Will

Used to express desire, preference, choice, or consent:

Auxiliary Verbs "Be", "Do", "Have"

An auxiliary verb helps the main (full) verb and is also called a "helping verb." With auxiliary verbs, you can write sentences in different tenses, moods, or voices. Auxiliary verbs are: be, do, have, will, shall, would, should, can, could, may, might, must, ought, etc. 

• I think I should study harder to master English.
• I am having a cup of coffee.
• You have been practicing hard.
• It was written by a petitioner.
• You may choose what you like.

The verb forms of be, do, and have can be used either as a main (full) verb or an auxiliary verb. The following examples show these verbs used as auxiliary verbs. 

1. "Be" as an auxiliary verb

Mood for Grammar

A mood shows the writer’s attitude toward what he/she is saying.

Indicative Mood states an actuality or fact.

• We will go to see a movie this Sunday.
• I’ll follow you.

Imperative Mood makes a request.

• Let’s go to see a movie this weekend!
• Please stop bugging me!

Subjunctive Mood expresses a doubtful condition (contrary to fact) and is often used with an "if" clause.