Meaning of PAIR in English
BAD : The old pair next door have been married for 65 years.
GOOD : The old couple next door have been married for 65 years.
Pair usually refers to things (e.g. 'a pair of scissors/socks') or to two people who are seen (doing something) together: 'It's about time the pair of you did some work.' 'The German pair need just two more points for the match.' Pair also refers to two animals that stay together and produce young: 'a pair of swifts with a family to feed'.
The usual word for a husband and wife (or two people in a similar relationship) is couple : 'Married couples should benefit from the new tax legislation.'
BAD : Have you always worn a pair of glasses?
GOOD : Have you always worn glasses?
Pair of is usually used for individual reference (NOT general reference): 'I've bought two pairs of shoes for the children.'
Compare: 'They sell shoes and handbags .' (NOT 'pairs of shoes')
Longman Common Errors English vocabulary. Английский словарь распространенных ошибок Longman. 2012