adjective
BAD : I was busy with cooking the dinner.
GOOD : I was busy cooking the dinner.
◆◆◆
be busy doing sth : 'She's busy trying to finish her thesis.'
Compare: 'I was busy with the housework.' 'I was busy doing the housework.'
adjective
BAD : I was busy with cooking the dinner.
GOOD : I was busy cooking the dinner.
◆◆◆
be busy doing sth : 'She's busy trying to finish her thesis.'
Compare: 'I was busy with the housework.' 'I was busy doing the housework.'
Longman Common Errors English vocabulary. Английский словарь распространенных ошибок Longman. 2012