► depend on to trust that someone or something will do something that you need or that you expect him or her to do:
You can depend on Jane - she always keeps her promises.► rely on AWL to trust that someone or something will do something that you need:
The city relies on the police to keep people safe.➔ Depend on and rely on have very similar meanings and you can usually use either expression in a sentence: I knew I could depend on you for help. | I knew I could rely on you for help.► count on to trust that someone or something will do something that you want. Count on is a little more informal than depend on or rely on:
I knew I could count on my older brother for protection.➔ You can also use count on to say that you expect someone to do something, even if it is not a good thing: You can always count on Jack to say the wrong thing.► be reliant on to rely on someone or something completely to do or provide something:
When she got older and could not drive, she was reliant on her family to take her to the supermarket, to church, and anywhere else she needed to go.► trust to feel sure that someone will do what he or she says or what is right:
David is one of my oldest friends - I trust him completely.I wouldn’t trust Tina to babysit - she is too immature.➔ Trust can also mean “to feel sure that something is correct or will work correctly”: She needs a car she can trust.