Hi! For me, ''off you go'' is kind of sweet, like sending a child off to school and hoping they have a good day. ''Get lost'' is a more polite way of saying ''F**k off'' without using the bad word - not quite as strong, but also not nice at all. ''Go away'' and ''leave me alone'' are about the same - ''leave me alone'' is a little more polite (you could add a ''Please''). Both of these are ''just the facts'' that you want to be left alone without adding anything nasty. ''Off with you'' I don't use as an American, but maybe Brits use it. I don't think any native English speaker would say ''Dismiss yourself'', unless in a classroom situation where I've heard teachers say ''You can dismiss yourself'', which means ''You can leave class now''. So for example, let's say someone you don't know is bothering you in the street, your reply from most polite to most strong. (Off you go - would not use as it's a friendly way of saying leave that you use with people you know/like) 1. Leave me alone, please. 2. Leave me alone. 3. Go away. 4. Get lost. 5. F**k off. And then of course there are about a thousand more creative ways to expand on #5. A lot of people also use #4 and #5 as a joking reply to being teased by friends, too (also ''Get out of here''), so you might hear them in TV/movies used that way.

It can be offensive if it's said in a condescending/patronizing way. Usually people at first excuse themselves when they want to stop talking to someone, rather than telling the other person to stop talking to them (so it will be, 'I have something to do, nice talking to you, bye'. If the other person keeps bothering them though, then you can be rude/direct as you want.