A phrasal verb is a verb used with a particle* (preposition) such as ‘at,’ ‘in,’ ‘out,’ or ‘up.’ Phrasal verbs are also called multi-word verbs, two- (or three)-word verbs, or verb phrases.
Phrasal Verbs are used constantly in casual conversation: "Did you find out what the boss wants?" "Not yet. He said he's looking for some kind of strange-named electronic gadget to impress his visitors, and he needs it before they show up next week. I'll call up my friend in engineering and ask him to look it up. He's good at coming up with quick fixes."
Not all phrasal verbs are idioms. Many have meanings that are quite obvious. In fact, some can be used with or without the particle (in cases where it just emphasizes the action of the verb): ‘clean’ or ‘clean up,’ ‘call someone’ or ‘call her up,’ ‘wash the dishes’ or ‘wash them up.’
Other times, however, the meaning of the verb is different with a particle/preposition added. Some verbs may be used with several prepositions, with a slightly different meaning in each case. Those are the verbs discussed on the rest of this page, as well as in the phrasal verb lists linked at the end of this page.
To see other examples using different particles with 'think' (as well as with take and other verbs), see List of Phrasal Verbs-2. For other common phrasals, see the lists at the bottom of this page.
If you want to use (not just understand) phrasal verbs, there is also a grammar point to learn. We use verb phrases in two ways. Some are separable: we can put a noun or pronoun between the verb and its particle.
For example, a mother wakes up her son, or she wakes her son up. For separable phrasals, if you use a pronoun it MUST go between the verb and particle: "She wakes him up." We never say ‘the mother wakes up him.’
Other multi-word verbs are inseparable. We cannot put anything between the verb and its particle. Dan takes after his father— or Dan takes after him. In English we cannot say ‘Dan takes him after’!
Any three (or more) word verb phrase will be inseparable. You need to learn if any two-word phrase you want to use is separable or not. There is a way to avoid this problem: do not separate verb and particle, and use a noun, not a pronoun, after the phrase. Verb+ particle+ noun is always acceptable.
One very common phrasal verb pattern is a verb + up. This pattern can illustrate the differences between phrasal verbs with the same meaning as the verb and a preposition used separately and phrasal idioms used as idioms.
Up not only can indicate a direction, but sometimes it acts as an intensifier, emphasizing the action of the verb.
Sometimes ‘up’ does change the meaning of the verb it follows.
See List of English Phrasal Verbs, A-M for to blow up, give up, hang up, hook up, look up, look up to someone, and make up (as well as many phrasal verbs with other particles).
See List of Phrasal Verbs, P-W for pick up, put up with, and show up, think up, turn up, use up, and wake up , as well as other phrasal verbs.
See List of Idioms for more detail on to be up to someone, as well as catch up (and many idioms not usng 'up.')
Idiom Examples demonstrates many phrasal verbs and other idioms as they are used in conversations. You can practice phrasal verbs with two memory (Concentration) games: Memory Game 1 (for Phrasal Verbs A-L) and Memory Game 2 (M-Z) or with the Phrasal Verbs Quiz.
For ESL teachers: I've combined the phrasal verb information from this page & the pages above with some new practice activities and many additional memory game cards into a seven-lesson, $4.00 pdf for ESL classes. It's a great way to give your students extensive practice using just under 100 of the most common phrasal verbs. See Common Phrasal Verbs: Examples, Matching, and Practice if you're interested.