Change and alter

All of my colleagues use the word “change” when they talking about a modification.
I decided to use sometimes the word “alter” instead of “change” but I’m not sure that “change” can be replaced by “alter” in every case.

Is there a situation when I shouldn’t use “alter” when I talking about a change?

I alter the computer setting or I alter my behaviour or I alter a sentence or I alter my life etc.

In all your examples you can substitute ‘alter’ for ‘change’. This can be done whenever ‘alter’ and ‘change’ both mean ‘to make (something) different’ or ‘to become different’, ‘to modify’ or ‘to vary’. However, ‘change’ is more commonly used.

He has changed since I last saw him; London has changed a lot in the last ten years. I would like to alter the time of my appointment; when he came out of prison he had altered completely.

Now, ‘alter’ is not used to mean:

  1. Put on different clothes: if you want me to mend the car, I’ll have to change into my old clothes.

  2. Give something in place of something else: can you change a $5 note? I must change the car tyres; she wants to change her travellers’ cheques.

  3. Get off one train to catch another which will take you to your destination: you will have to change (trains) at Birmingham.