The words a, an and the are types of adjectives called articles.
A  and an are called indefinite articles.
   A  is used before singular count nouns.
   A  car, a book, a child, a holiday
An  is used with count nouns beginning with a vowel sound.
   An  apple, an elephant and notice; an hour but a European. ( the 'h' in hour is  silent. The 'e' in European is not a vowel sound)
A  conjunctive adverb is a word that connects two clauses to make them one  sentence. These adverbs make the sentence shorter.
   When  you use a conjunctive adverb, put a comma (,) after it. You can also use a  semicolon (;).
The weather was not very good on our last holiday in Sweden; however, we still had a good time.
These are some conjunctive adverbs: also, besides, consequently, finally, however, indeed, instead, meanwhile, next, still, then etc.
Of  – belonging to, connected with, related to
   This  is a collection of romantic stories.
   I  always dreamed of being famous.
   He  wrote letters of love to me.
   This  is the best part of the film.
Of  – to say what/when/where
   I  graduated in the autumn of 1999
   This  is a picture of my son.
 He  is the owner of the restaurant.
Can  – for ability
   I  can dance Tango.
   She  can't sing.
   Can  you speak English?
Can  – for permission
   Can  I sit here?
   Can  we leave now?
 Can  I play some music?
Can  – for requests or suggestions
   Can  we have more coffee?
   Can  I have the bill?
   You  can go wherever you like.
All  modal verbs are auxiliary verbs, which means they can only be used with a main  verb. Modal verbs cannot be a main verb.
   The  modal verbs are; will, would, shall, should, can, could, may, might and must.  In this module we focus on will and would, and shall and should.
Will  is used to show desire, preference, choice or consent:
   I  will accept your offer.
 Will  you please be quiet?
Auxiliary verbs help the main verb and are in fact also referred to as 'helping' verbs. Auxiliary verbs are: be, do and have. Modal verbs are also auxiliary verbs but we are going to focus on be, do and have in this module.
The verbs be, do and have can also be used as main verbs or as auxiliary verbs. Here are examples of be, do and have as main verbs:
A preposition links a noun, pronoun or noun phrase to some part of the sentence. Prepositions are always difficult to learn therefore you should practise using the prepositions with the correct phrases or nouns.
Here are few examples of on, at, or in:
On  – to show a surface of something
   I  put my phone on the table.
   Don’t  leave any important papers on your desk.
Comparative adjectives compare two things. Superlative adjectives compare more than two things.
Forming comparatives and superlatives:
Adjectives that have only one syllable (part) or adjectives that end in 'y' use ‘er’ to form comparatives and 'est' to form superlatives. For adjectives that end in 'y' change the 'y' to 'i' before adding 'er' or 'est'.
Verbs  are either in the active voice or in the passive voice. In the active voice the  relationship between the verb and the subject is clear:
   The  company gave Paul a car.
   This  sentence is active. The company (subject) gave (verb)
In  the passive the subject of the sentence is not the 'doer'; the person doing the  action. 
   Paul  was given a company car.
Verbs  that show actions or 'action verbs' are the most used verbs. 
 Action  verbs take 's' in the third person when they are singular verbs:
 He  lives in Athens.
 She  works in the city.
 It  rains a lot in February.
Negative  sentences need 'do not', 'does not', or 'did not'.
   He  does not live in Athens.
   She  does not work in the city.
   It  does not rain in August.
 It  did not rain in June.