What is the difference between 'por' and 'para'?

These two prepositions can be confusing because they can both be translated to 'for' in English. To understand how and when to use them, you need to think about their purpose in the sentence. This takes practise when speaking, but when writing you can use the following rules. They are not exhaustive but it should give you a good start. 'Por' is used to:express gratitude ("Thank you for the gift" = "Gracias por el regalo")To decribe how you moved i.e. by, through, around etc. ("I went through the streets of Madrid" = Fui por las calles de Madrid)To describe the duration of something (I waited for one hour" = Esperé por una hora)To say why/the cause of something (I slipped because of the ice = Resbalé por el hielo)Meaning in support of or working for (I work for my money = Trabajo por mi dinero). 'Para' is used for: Meaning 'for the purpose of' (I need a pan to cook/forcooking = Necesito una sartén para cocinar)To direct an object (noun or pronoun) at a person (The book is for her = El libro es para ella) For deadlines (I want it by/for tomorrow = Lo quiero para mańana).