Study English in the UK (Short-term study visa)
Detailed information by the Government:
https://www.gov.uk/visa-to-study-english/eligibility
Overview:
Who can apply
You must be 16 or older to apply.
You must prove that:
you’ve been accepted onto an English language course that lasts 11 months or less and includes no other subjects
your course is with an accredited institution
you have enough money to support yourself without working or help from public funds, or that relatives and friends can support and house you
you can pay for your return or onward journey
If you’re under 18 you must also:
have made arrangements for your travel and stay in the UK
have the consent of your parent or guardian to study in the UK