different titles at once

[mollykins]

How many titles can you legally use at the start of your name in one go?

I may be slightly mistaken, but I think i heard someone called Professor, Sir ????? ?????

[bednobs]

as many as you want

[mollykins]

I didn't know if there was a limit, up until a couple of weeks ago, i'd never heard of anyone with more than one . . . . But if you have two titles for similar things ie doctor and professor, you only call yourself professor, not both, because prof is higher ranking than a dr.

[mollykins]

And thre's a nurse with a phd, who you'd call nurse doctor ----- ----------- or would it be doctor nurse ------- ----------- ????

[bednobs]

Nurse isn't really a prefix title. I wouldn't calle myself "nurse bednobs" or "mrs Nurse Bednobs" in the situation you describe, to avaoid confusion (if for example i was a nurse working as a nurse in a situation i wouldn't want to be mistaken for a medical doctor but still wanted to show off I Would write Mrs bednobs PhD, RN ) but i can't think of many situations where you would need to write that.
However, if i wasn't in a situation where it would cause confusion, i could call myself Dr bednobs