"Make somebody something" is equivalent to FORCING them to do something against their will. If someone makes you do something, you do it because you have no choice. For example, "The police arrested the man and made him lie on the floor. ". If students day "The teacher made us do a test", we get the impression that they were unhappy about this. The construction "get somebody do something" does not exist. Do you mean " get someone TO do something" ? This can mean to ask or arrange for someone to do something, often as part of their job. For example 'I'll get my PA to contact you" or "I'll get the gardener to cut the grass". It can also mean 'persuade', as in 'Why don't you get your boyfriend to take you to that nice restaurant?'.