it's pretty clear on the set (m) form and guidance notes
from
http://www.bia.homeoffice.gov.uk/sit.../guidesetm1108
Does this requirement apply to everyone?
It does not apply to anyone under the age of 18 or aged
65 or over at the time the application is made.
Anyone with a significant physical and/or mental health
condition(s) or incapacity may be exempt if it prevents
them from studying for and taking the Life in the UK test
or from studying for an ESOL qualification . Exemption on these grounds will only be given in exceptional cases.
If your partner is a permanent member of HM
Diplomatic Service, or a comparable UK-based staff
member of the British Council on a tour of duty abroad,
or a staff member of the Department for International
Development, a designated person (normally the head
of the post at which your partner is based) may certify
that you have a sufficient knowledge of the English language
and life in the UK for the purpose of settlement.
