Causative Verb

The causatives are the verbs that are used to indicate that one person causes another person to do something for the first person. One can cause somebody to do something for him/her by asking, paying, requesting, or forcing the person.

Have: to give someone the responsibility to do something
> S + have(any tense) + object (usually person) + base form of verb
   Ex: Dr. Smith had his nurse take the patient's temperature.
          Please have your secretary fax me the information.
          I had the mechanic check the brakes, She has her assistant make coffee every morning
> S + have (any tense) + object (usually thing) + past participle form of verb
   Ex: John had his car washed
         He always has his work done.
         Mary will have her homework prepared.

Get: to convince/persuade someone to do something/ to trick someone into doing something
> S + get (any tense) + object (usually person) + to infinitive 
   Ex: Susie got her son to take the medicine even though it tasted terrible, 
          My best friend got me to tell her the rumor
          How can parents get their children to read more?
          The government TV commercials are trying to get people to stop smoking.

> S + get (any tense) + object (usually thing) + past participle form of verb
   Ex: John got his car washed.
         He always gets his work done.
         Mary will get her homework prepared.

Sometimes "get someone to do something" is interchangeable with "have someone do something," but these expressions do not mean exactly the same thing.
> I got the mechanic to check my brakes (At first the mechanic didn't think it was necessary, but I convinced him to check the brakes)
> I had the mechanic check my brakes (I asked the mechanic to check the brakes)

Make: to force someone to do something
> S + make (any tense) + object (always person) + base form of verb
   Ex: My teacher made me apologize for what I had said.
          Did somebody make you wear that ugly hat?
          She made her children do their homework.
          Robert made me beat that little child.  
          He always makes me do his work.
          Mary will make me prepare her homework.  
          I made him wash my car, My boss made me work on the weekend
          He makes me laugh whenever I am down.

Let: to allow/permit someone to do something
> S + let (any tense) + object (always person) + base form of verb
   Ex: John let me drive his new car, My manager let me kick off the meeting. 
          Will your parents let you go to the party?
          I don't know if my boss will let me take the day off.
> S + permit/allow + object + to infinitive
   Ex: John allowed him to drive his car
          He always allows him to do that
          The teacher allowed me to sit for the exams

Help: not actually a causative verb either but is generally regarded as a causative verb because of its grammatical use in a sentence
> S + help (any tense) + object (usually person) + base form of verb
   Ex: Robert helped me escape the prison
          He helps me prepare my presentations
          The teacher had helped the students understand a complex theory
          I helped him learn driving
          It will help you move on
> S + help + object + to infinitive
   Ex: John helped him to lift his car
          He always helps me to find my stuff
          The teacher helped me to understand the topic

Practice Here and Here