For ESL learners, the big confusion between "with" and "by" is when they refer to HOW something is done. If that is the question, the answer is simple: The word "with" is generally paired with a NOUN. The word "by" is generally paired with a VERB (or some verbal form). Another way to think about it is this: "with" something "by" doing Ex.: "Many drinks are sweetened WITH SUGAR." Ex.: "Many drinks are sweetened BY ADDING sugar." Ex. 2: "The nail can be removed WITH A HAMMER." Ex. 2: "The nail can be removed BY USING the back of a hammer." Ex. 3: "Try to stop the bleeding WITH PRESSURE." Ex. 3: "Try to stop the bleeding BY APPLYING pressure." Be careful! Some verbals ending in "-ing" can work with EITHER "with" or "by": Ex. 4: "The problem won't be solved WITH CRYING." Ex. 4: "The problem won't be solved BY CRYING." The examples above both work; however, it is still better, for clarity, to change the first of the two, using a true noun (instead of a verbal / gerund): Ex. 4b: "The problem won't be solved WITH TEARS." One exception is when the HOW question is about transportation. Here, we use "by": Ex. 1: "I went to the airport BY TAXI." (not "taking a taxi") Ex. 2: "Can you get to that town BY BUS?" (not "by riding a bus") Either way for these examples is grammatically CORRECT; but we only say "by bus", "by taxi", "by car", etc., in real conversation.

Hello Monti, WITH: You use with in different ways. You can use it to talk about something, then add ( ) more things to it. E.g "Could I have coffee with sugar and milk?" In this example you asking for coffee, but you want to add ( ) milk and sugar. E.g. "Can I have the Ice cream with the cherry on top." In this example the ice cream you want has the cherry (the added thing), the others don't or may have other things on top. You can 'add' ( ) people. E.g. "Please, come with me." You want to add someone/some people to you and then go somewhere together. E.g. "Would you like to go to the cinema with me?" In this example you are asking other people to go to the cinema. You can use with to ask for support. E.g. "We should tell the boss, he's bad. Are you with me?" This time you want a group of people to tell the boss he's bad. I've got to go now. I hope that helps in some way.