Use of the wrong tense

Using a wrong tense with an improbable condition.

Don’t say: If he would/’d ask me, I would/’d stay.

ü Say: If he asked me, I would/’d stay.

Express an improbable condition by the past tense and use the conditional in the main clause. This use of the past tense doesn’t indicate a time but a degree of probability.

Use of the wrong tense

Using will/’ll instead of would/’d in a subordinate clause.

Don’t say: He said (that) he will/’ll come tomorrow.

ü Say: He said (that) he would/’d come tomorrow.

Will/’ll changes to would/’d in subordinate clauses, when the verb in the main clause is in past tense.