有频度副词的句子怎样变否定句?
Traffic police usually give you a ticket if you park your car in the wrong place.
这句的否定句应该怎样改?
Traffic police don't usually give you a ticket if you park your car in the wrong place.这里的don't应放在其前还是后?还是别的地方?
I sometimes go for a walk after dinner这句可否改成否定句呢?