Phrasal verbs, also called two-word verbs, are idiomatic expressions wherein the second element of the verb (the adverb or particle) is not necessarily predictable.
Phrasal Verb:
stand up
Meaning / Example:
1. to arise from a sitting or reclining position. > He stood up and looked across the valley. > She had been sitting for so long that it was a pleasure to stand up.
2. to be in a standing position. > I stood up throughout the whole trip because there were no more seats on the train.
3. to wear well; to remain sound and intact. > This material just doesn't stand up well when it's washed. > Her work doesn't stand up under close scrutiny.
4. [for an assertion] to remain believable. > His testimony will not stand up in court.
Phrasal verbs are multi-word verbs that, like single-word verbs, convey action of the body or mind or occurrences. Phrasal verbs consist of a basic verb + another word or words, usually a preposition or adverb. Example: speak (basic verb) + up (preposition)