To..., for... and so that...

Look at these examples:

- I phoned the restaurant to reserve a table.

- What do you need to make bread.

- We shouted to warn everybody of the danger.

- This letter is to confirm the decisions we made at our meeting last week.

- The president has a team of bodyguards to protect him.

In these examples the word 'to' tells us the purpose of something: why somebody does something, has something, needs something etc., or why something exists.

 

You can say 'for somebody to do something':

- There weren't any chairs for us to sit on, so we sat on the floor.

You can use for -ing or to... to talk about the general purpose of something, or what it is generally used for:

- I use this brush for washing the dishes.         or                       ...to wash the dishes.

 

We use so that especially:

When the purpose is negative

- I hurried so that I wouldn't be late.

 

with can and could

- She's learning English so that she can study in Canada.

 

You can leave out that. So you can say:

- I hurried so that I wouldn't be late.       or            I hurried so I wouldn't be late.