Error 1
(Incorrect): Though he is fat, still he runs fast.
(Correct): Though he is fat, he runs fast.
(Incorrect): As he is fast, so he can’t run fast.
(Correct): As he is fast, he can’t run fast. OR He is fat, so he can’t run fast.
(Incorrect): As I took aim at that time he shook my arm.
(Correct): As I took aim he shook my arm.
In English, one conjunction is enough to join two clauses – we do not normally use two.
Error 2
(Incorrect): Because he was not ready therefore we left without him.
(Correct): Because he was not ready we left without him.
The conjunction because is enough to join the two clauses. There is no need to use a second conjunction like therefore or so.
Error 3
(Incorrect): She did not come to school. Because she was ill.
(Correct): She did not come to school because she was ill.
This is a common punctuation mistake. Because is a subordinating conjunction and must never be separated from its main clause by a full stop.
Error 4
(Incorrect): No sooner I had reached the station than the train left.
(Correct): No sooner had I reached the station than the train left.
When no sooner comes at the beginning of a sentence, we use an inverted word order. That means the auxiliary verb comes before the subject.
(Incorrect): Neither he comes nor he writes.
(Correct): Neither does he come nor does he write.
When the first word of the sentence is negative, the auxiliary verb comes before the subject. Note that the sentence ‘He neither comes nor writes’ is equally right and probably more common.
Error 5
(Incorrect): Their front door was open and there was nobody at home.
(Correct): Their front door was open but there was nobody at home.
But is the conjunction to use when the second main clause gives unexpected information.