Phrasal verbs are idiomatic expressions in English that are formed by combining a verb with a preposition or adverb. This creates a new meaning that is different from the single verb alone. Some common phrasal verbs in English include "break down" which means to stop working, "break up" which means to end a relationship, and "turn on/off" which means to power electronics on or off. Phrasal verbs are widely used in both written and spoken English. The document provides examples of several other commonly used phrasal verbs in English and their meanings.