First, I'll answer the question you've asked: What is the difference between 'to' and 'for'? 'To' and 'for' are different words. They're prepositions with completely different meanings and uses. Each has to be used in the appropriate context. Now I'll answer the question which I think you meant to ask: 'When I want to translate xxxxx from Spanish to English, why does the English sentence sometimes use 'to' and sometimes use 'for'? I'm confused. Aren't they the same?' No, they're not. What you have to understand is that you cannot translate prepositions directly from one language to another. It is impossible to say that 'por' in Spanish is always 'for' in English, for example, or vice versa. Languages don't work that way. Don't try to translate prepositions - or any other grammatical feature - directly from one language to another. Don't try to translate English or Spanish phrases word for word. You'll just make mistakes and get confused and frustrated. So what should you do? Quite simply, you need to COMPLETE PHRASES in English. Learn that it is correct to say, for example, 'I want to go to the USA next year TO learn English.' That's a correct sentence - learn it and use it.

Hi Ana,your question is much too general.Can you give me a specific context? To and for have many different uses in English, so I don't know what you are referring to.