verb
BAD : Those who approve the death penalty claim that life imprisonment is not effective.
GOOD : Those who approve of the death penalty claim that life imprisonment is not effective.
BAD : Some husbands do not approve the idea of their wives having a job.
GOOD : Some husbands do not approve of the idea of their wives having a job.
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approve sth (without of ) = formally accept a plan, proposal or application: 'The use of the new drug has yet to be approved by the Medical Research Council.'
approve of sb/sth = think that someone or something is good: 'I'm sure that most athletes will approve of the new rules on drug testing.' 'I don't approve of sending young children to boarding school.'