For.

[allen1984]

If you pay extra one pound, we will give you one burger for free

For temporary, you can call me this name

can anyone explain the red parts to me, if they are correct
thanks a lot

 

[kalyson]

If you pay extra one pound, we will give you one burger for free.

This sentence is not correct. It is better to say:

If you pay one extra pound, we will give you one burger for free.
OR
If you pay an extra pound, we will give you one burger for free.

I'm not sure what the extra pound is for, but the person is saying that if you pay extra you will get another burger. I don't see how it is free, though, since "free" means it should cost nothing.

For temporary, you can call me this name.

This is incorrect. It should be:

Temporarily, you can call me this name.

It just means that for now you can call me this name, but maybe not later.