)3. if we (not to like) his suggestion, we (to tell) him about it. 4. if john (to want ) the advice, he (to ask) you. 5. if his sister (to have) better qualification, she (to be able to) apply for better job. 6. they (to find) the solution, if they (to understand) the problem.

3. If we (do not like) his suggestion, we (will tell) him about it.
4. If John (wants ) the advice, he (will ask) you.
5. If his sister (has) better qualification, she (will be able to) apply for better job.
6. They (will find) the solution if they ( understand) the problem.