Stop + -ing form or to-infinitive

We use the -ing form after stop to indicate that an action or event is no longer continuing:

• It’s stopped raining. Let’s go for a walk. (It was raining, but not any more.)
• We’ve stopped using plastic bags in supermarkets. We take our own bag with us now when we go shopping.

We use the *to-*infinitive after stop to indicate that someone stops doing something in order to do something else:

• On the way to Edinburgh, we stopped to look at an old castle. (We were travelling, then we stopped our journey in order to look at the castle.)
• We stopped to have something to eat.