Sue is a verb, I don't think "a sue" is used. It means you start legal proceedings against someone, e.g. you intend to go to court. * Samsung and Apple are always suing each other Claim can be a verb or a noun: verb: to say something is true (without proof) OR to say you are entitled to something noun: a statement that something is true OR a demand for something you think you are entitled to * He claimed that he had been sober * The court had denied their claims to asylum So both "sue" and the second meaning of "claim" are related to court stuff, which perhaps causes the confusion.

'A Sue' is a girl named Sue. To sue in the sense that I think you are asking about is a verb only. I think that to sue is to make a claim for compensation against someone in court - at least that is common understanding. A lawyer may say otherwise. A claim can be any sort of claim. You can claim for a warranty repair. You can make an insurance claim. Here - we have a 'small claims tribunal' where you can make a claim against someone.

I am going to make a claim....Voy a hacer una reclamación I am going to sue...Voy a demandar