- If two subjects used in a sentence do not have the same number, use separate auxiliaries for both of them.
Example –
Incorrect - Five apples sold and one were purchased.
Correct - Five apples were sold and one was purchased.
- A single verb should be used for a subject only when the form of the verb is the same for both the subjects.
Example –
Incorrect - I am intelligent and my sister creative.
Correct - I am intelligent and my sister is creative.
Maya is sixteen and Tushita (is) twenty. (Correct)
- A Past Tense in the main clause should be followed by a Past Tense in the subordinate clause.
Example –
Incorrect - Pratima failed because she misses classes.
Correct - Pratima failed because she missed classes.
- A Past Tense in the main clause can be followed by a Present Tense in the subordinate clause when the subordinate clause expresses a universal truth.
Example –
Incorrect - We were told that the Earth moved round the sun.
Correct - We were told that the Earth moves round the sun.
- Modal auxiliaries are not used together, but they can be connected by a conjunction.
Example –
Incorrect - You should must come.
Correct - You should and must come.