I have just been sent a form by a solicitor. In it, I am asked: "Have you attended upon hospital since your accident?" Is this some kind of legal-speak or am I right in thinking that the phrase "attended upon has been used incorrectly. To my knowledge, "attend upon" means to serve, administer, wait on, follow or escort. Have they made a grammatical error or have I?? Thank you.

Hi,

It's the kind of formal and archaic phrase that some members of the legal profession seem to like. It means 'to visit, keep an appointmet with, often on a regular basis'. If you read 19th. century (or earlier) novels, you'll find sentences like 'Yesterday I attended upon Lady Randolph', meaning I visited her, probably because I had an obligation to do so.

This is from the famous 17th.century Diary of Samuel Pepys.
So to dinner, and then away by coach to the Temple, and then for speed by
water thence to White Hall, and there to our usual attending the Duke of
York, and did attend him, where among other things I did present and
lodge my letter, 

Best wishes, Clive