Hi Wallisson, I hope these examples are helpful to you: "She is not the person you should be with." "Hammers are the tools you need to strike nails with." "Dishonesty is the one trait I will not put up with." "So far, we don't have a lot of information to work with." "His uncle's passing was very hard for him to cope with." You may have learned a rule about not ending sentences with prepositions (such as "with"), but that's a Latin rule that never really fit well with English. It was a rule that the elite classes tried to force English to follow centuries ago, but it really has no bearing on today's standard conversational English.

She is the last girl I want to travel with.

So, all of that also applies to 'with'. Again, examples in Portuguese and in English for you to compare: "Ela é a pessoa com a qual eu estava conversando." "Ela é a pessoa com que eu estava conversando." "Ela é a pessoa que eu estava conversando." "She's the one with whom/who I was talking." "She's the one whom/who/that I was talking with." "She's the one I was talking with." In addition to that, there are also some fixed phrases that you have to keep together when moving them around, such as 'to begin with': "To begin with, I didn't know that." "I didn't know that, to begin with." Some grammarians, as Mr. Zhang said, grimace at the use of prepositions at the end of sentences. But this is current use of the language; it is natural and perfectly okay. If you think about a phrasal verb like 'to put up with', it would be extremely formal and strange not to use those prepositions at the end of a sentence like 'this is the kind of behaviour I can't put up with'. I don't even know how it would be supposed to be.

Hey, Wallisson, I know this concept is hard for us, Portuguese speakers, to understand at first, because in Portuguese we can just leave out some prepositions in an informal register of the language, especially when we change the word and phrase order, and the meaning of the sentence is not affected. For example: "Sonhei com tudo aquilo." "Tudo aquilo com que sonhei." (Changing the order; more formal and grammatically correct.) "Tudo aquilo que sonhei." (Without the preposition.) In English, as a rule of thumb, that is not possible, even in informal speech. You can move the preposition around, because that makes the sentence more natural and fluid, but you have to keep it. So, those same sentences above would be: "I dreamed about all that." "Everything about which I dreamed." (Changing the order, but almost no one says this in real life, it's extremely formal.) "Everything which/that I dreamed about." (Moving the preposition. You can keep 'which' or use 'that' now.) "Everything I dreamed about." (Removing 'which/that'; probably the most common way of saying this.) You know that in Portuguese we can substitute 'que' for almost every other relative pronoun ('o qual', 'quem', etc), but we have to keep it when we get rid of the prepositions. In English, you can completely leave out determiners or conjuctions such as 'which' and 'that', but you have to keep the preposition and move it to after the verb. Another example in Portuguese and then in English, so you can compare the syntax differences between them: "A cadeira na qual eu estava sentado estava me machucando." "A cadeira em que eu estava sentado estava me machucando." (Substituting 'que' for 'qual'.) "A cadeira que eu estava sentado estava me machucando." (Removing the preposition, but we have to keep 'que'). "The chair on which I was sitting was hurting me." "The chair which/that I was sitting on was hurting me." (Moving the preposition.) "The chair I was sitting on was hurting me." (Removing 'which/that'.)