Phrasal verb is a group of verbs that has a different meaning of the previous original verb by adding one or more prepositions or adverbs after it.
For examples:
on, as in, Turn on
out, as in, get out
after, as in, look after
for, as in, look for
up, as in, give up
The words /on/, /out/, /after/, /for/ or /up/ is called Preposition (see Structure of Preposition in this blog). Those words are used to form phrasal verbs. The uses of the preposition in creating phrasal verbs has their own function. The existance of the prepositions in the phrasal verbs depend on the meaning when they are added behind the original verbs.
From many cases I can see that there are two meanings created by adding prepositions at the original verbs, they are;
1.The meaning denotes the direction or place or time. In other words, the addition of preposition there creates adverb of direction or place and adverb of time. We, then, call this type "Nominal Phrasal Verbs". I call like this because the addition of preposition at the original verb doesn't change the meaning completely.
2.The addition of preposition changes the meaning completely which is different of when the original verb stands alone without the preposition. We call this type "Verbal Phrasal Verb". It is because the change in meaning makes new and different completely meaning as if it was not phrasal verb but a real verb like original verb I discussed above.
For examples:
/Stand up/
The preposition /up/ doesn't change the meaning of the verb /stand/ as the original verb. Here, /up/ is to emphasize the existance of /stand/. In other words, /up/ determines the adverb of direction.
/Give up/
The phrasal verb, here, means "to stop" or "to surrender" from something or an activity/action. The preposition /up/ has changed the original meaning of the verb /give/. In other words, the addition creates a new meaning and completely different of the original meaning of the original verb.
BASIC TYPES OF PHRASAL VERBS (STRUCTURE OF PHRASAL VERBS)
Basic types of phrasal verbs here is to talk about the structure of phrasal verb in a sentence. As you know that phrasal verb is also a verb but different in physical appearance and Existance. The structure of phrasal verb, then, will discuss about the relation between the verb and the object (either in noun or pronoun).
TYPE I
When the object is a full noun, the preposition may come either before or after it. But, when the object is in pronoun (Objective pronoun), the objective pronoun is placed between the verb and the preposition/particle.
For examples:
Full noun:
The strange man takes out his gun
or, you can also say : The strange man takes his gun out.
Objective Pronoun:
The strange man takes it out
Study this following illustration!
TYPE II
Phrasal verb in Type II adds other preposition beside the preposition in the phrasal verb. Let's say that the preposition which is used in phrasal verb is "Particle".
For example:
The child doesn't dare to look up to his parent's eyes.
In the sentence above we can see that there is another beside the preposition in /look up/, that is /to/. So, there are two prepositions are used here; /up/ and /to/
Study this follows!
Notice that the both particle and preposition denotes an adverb of direction.
TYPE III
In this type, we will discuss more about the particle which is placed after the original verb. Like I discussed before, When preposition is placed or added after the original verb and makes a phrasal verb, the meaning will completely be different of the original verb. In other words, the preposition doesn't denotes the adverb of time or direction. Here, we call it "participle" not preposition.
Compare this follows!
1) Let's go into the problem deeply
2) Let's go into the dining room .
(Taken from Kernel Lesson Plus - A Post Intermediate Course By Robert O'neill)
American Kernel Lessons Intermediate Student Book (Longman American English)
From the two sentences above, we find different in meaning even though the structure of the phrasal verbs are similar.
In sentence 1), /into/ is a particle (part of the verb /go/). And, in sentence 2), /into/ is a true preposition (direction or place).
TYPE IV
The phrasal verbs in this type are used intransitively. It consists of Verb and The particle.
For examples:
I bore up.
The word /up/ here is the particle of the verb /bore/ in one phrasal verb. When the particle is omitted and let the verb stands alone, the meaning will be very far different.
Study this following example deeply!
Tell her to bear up! (e.g. to encourage from misfortune).