Many English verbs can be followed by prepositions or adverb particles. These combinations are often called phrasal verbs. There are numerous phrasal verbs in English. It is not easy to learn all of them; it is not necessary either. However, you must be familiar with the most important ones.
Are phrasal verbs important?
Phrasal verbs are not commonly used in formal writing. Instead, people use one-word verbs that express the same idea. On the other hand, phrasal verbs are very common in the speech of native English speakers. So if you live in an English speaking country where you have to converse with native English speakers on a regular basis, learning phrasal verbs is a must. The problem with phrasal verbs is that you can’t guess their meaning because the meaning of a phrasal verb is sometimes very different from the meanings of the two parts taken separately. That means, you have to make a conscious effort to learn them.
Separable and non-separable phrasal verb
Phrasal verbs can be separable or non-separable. The adverb particle in a separable phrasal verb can go before or after a noun object. When the object is a pronoun, the particle always goes after the object.
She switched off the TV. OR She switched the TV off. (Switch off is a separable phrasal verb. That means the particle off can go before or after the object TV.)
She switched it off. (NOT She switched off it.) (When the object is a pronoun, the particle always goes after it.)
The two parts of a non-separable phrasal verb cannot be separated.
She fell off the horse. (NOT She fell the horse off. Fell off is a non-separable phrasal verb.)