noun
BAD : The key of our success is that we all worked very hard.
GOOD : The key to our success is that we all worked very hard.
◆◆◆
key to a problem or situation: 'The key to inflation is control of the money supply.'
noun
BAD : The key of our success is that we all worked very hard.
GOOD : The key to our success is that we all worked very hard.
◆◆◆
key to a problem or situation: 'The key to inflation is control of the money supply.'
Longman Common Errors English vocabulary. Английский словарь распространенных ошибок Longman. 2012