Must I, shoud I or do I have to?

Must, should and Have to

When we talk about obligation we use must, should and have to. But the meaning of these words is not the same.

Should is used when ‘it is better if’. It is not necessary, the obligation is not 100%, but it is better if:

I should clean my house. Nobody is forcing me to clean my house, but it is better if I clean it.

I should phone Peter

I should take more exercise

I should study harder.

None of the above things are necessary but it is better if they were done.

When we say ‘should’ there is a 50:50 obligation. It is not necessary, it is better.

The next form of obligation is when I tell myself to do something. I tell myself. Other people don’t tell me, I tell myself. Here, we use ‘must’.

I must tidy my bedroom. This is me telling myself to clean the room, not my mother.

I must go. My decision.

I must be a better person. I have decided that it is necessary.

But sometimes, other people oblige me to do something. Maybe my parents, or my school or the government. In this case we use ‘have to’.

I have to pay tax. The government says so.

I have to be in school at nine. The principle says so.

I have to tidy my bedroom. My mother says so.

So which do you think is the strongest? It's debatable, but probably have to. It’s stronger because the obligation comes from others, not ourselves.

Be careful with the negatives though. They are NOT the opposite!

I don’t have to, means it is not necessary, but I can if I want.

I don’t have to go to school on Saturday. (But I can if I want!)

I mustn’t is very strong. I means it is necessary that I don’t.

You mustn’t smoke in school. It is prohibited!

Children mustn’t play with matches. It’s dangerous!

I don't have to go to school on Saturdays.

He doesn't have to work because he is rich.

And now, unfortunately, I have to go! Bye bye.