Few quick tips

1). There is -- considered wordy and may be frequently be omitted to create a more concise sentence.

2). When more is used in the comparative form of an adjective (more difficult) or adverb (more likely), it is followed by than.

3). They or it should not be used without definite antecedents. It must always be able to replace a noun.

e.g -- In that store they make a customer feel stupid.--- they is referring to whom? Here use of they is incorrect as there is no antecedent for they in this sentence so instead of they a proper noun should be used.

Note:In expressions of time and weather antecedent of it is not given.

e.g -- It is too hot today.

4). Subject form of pronoun always comes after ‘than’ or ‘as’.

e.g -- Peggy is smaller than I (am).

5). Because of is not same as caused by. An adverbial phrase beginning with because of answers the question "why" ?

e.g -- He is distrusted because of his deviousness. Here because of his deviousness is an adverbial phrase.

Why is he distrusted ? because of his deviousness.

6). Due to means caused by - Use due to only if it can be substituted by caused by.

7). Even if is used in conditional sentences to mean 'it doesn't matter if'.

e.g -- I will go on a tour of Europe next year even if none of you want to come with me.

8). We use a singular verb with the phrase the number of.

e.g -- The number of club members has increased this year.

9). We use a plural verb with the phrase a number of.

e.g -- A number of students were absent today.

10). Use of IN

i). IN + year / month / season

e.g -- in 1988 ; in september ; in winter ; in 21st century

ii). IN + a week or more

e.g -- in the easter holiday ; in the summer term

iii). IN + part of day

e.g -- in the morning ; in the evening

11). Use of ON

i). ON + day / date

e.g -- on wednesday ; on 15 April ; on that day

ii). ON + a single day

e.g -- on Easter monday ; on Christmas Day

iii). ON + day + part of day

e.g -- on Friday morning ; on Tuesday evening

12). Use of AT

i). AT + clock time / meal time

e.g -- at three o'clock ; at lunch (- time) ; at that time ; at the moment

ii). AT + two or three days

e.g -- at Easter / Christmas ; at the weekend (US : on the weekend)

Note - Exceptions - I woke up in the night (= in the middle of the night) ; It happened on Monday night ; I can't sleep at night (= when it is night)

13). We do not use in, on, or at before every, last, next, this, tomorrow and yesterday.

14). In time means 'early enough'

15). On time means at the right time , on schedule

I will keep updating this post .