23. Focus on: two-word phrasal verbs that require an additional particle when used with an object, 2

As we saw in Section 9, many phrasal verbs that can be used both intransitively and transitively require a second particle when they are used transitively, which makes them three-word phrasal verbs.

Although these phrasal verbs have a three-word version, they remain classified as two-word verbs because the two-word and three-word phrasal verbs have the same meaning — they are variations of the same verb:

He filled in. He filled in for Mike.

There are, however, three-word phrasal verbs that share the same verb and first particle as another two-word phrasal verb but have an entirely different meaning. These are two different phrasal verbs and are classified separately:

He put up a poster.

He put up with her rudeness.

1. crack down (on) p.v. When you crack down or crack down on someone or something, you enforce rules and laws more than you enforced them before or you make new, stronger rules and laws.

The chief of police said he was going to crack down on car theft.

The students have been coming to class later and later everyday. It's time to start cracking down.

crackdown n. When you enforce rules and laws more than you enforced them before, this is a crackdown.

The FBI is planning a major crackdown on organized crime.

After the crackdown, the crime rate plunged.