Why should I have to do this?

Question

Debaashish in India asked: What's the difference between "Why should I do this?" and "Why should I have to do this?"

Answer

The difference between these two questions has to do with the meanings of the two modal expressions should and have to.

• Should is used to give advice. It means that something is the appropriate, reasonable, or best thing to do. 
• Have to is used with rules and orders. It is stronger than should, and it means “must, or be required to.”  

Therefore, the first sentence (“Why should I do this?”) means “Why is this best thing for me to do?” or “What good reason is there for me to do this?”

And the second sentence ("Why should I have to do this?") means “What good reason is there for me to be required to do this?”

I hope this helps.