If one opens a fixed term deposit, say 3 Months at 2.375% what happens at the end of the three months? Does the account revert back to basic rate of 0.75%?

If, towards the end of the 3 months; you revisit the bank and ask for another 3 month term, what if the rates have changed? Is the interest compounded from the first 3 months?

Explanations welcome. I did try asking in the bank but we could not make ourselves understood.

You will no doubt find that the %age you quoted is an annualised rate, don't expect that return for 3 months. Also they have probably compounded it, but will pay you simple interest.

You should have a form (which is generally translated) with a tick box to either roll it over at the prevailing rate, or deposit back to your savings a/c.