Phrasal verbs are part of a large group of verbs called "multi-word verbs". Phrasal verbs and other multi-word verbs are an important part of the English language. Multi-word verbs, including phrasal verbs, are very common, especially in spoken English. A multi-word verb is a verb like "pick up", "turn on" or "get on with". For convenience, many people refer to all multi-word verbs as phrasal verbs. These verbs consist of a basic verb + another word or words. The other word(s) can be prepositions and/or adverbs. The two or three words that make up multi-word verbs form a short "phrase" - which is why these verbs are often all called "phrasal verbs".
Grammar is the system of a language. People sometimes describe grammar as the "rules" of a language; but in fact no language has rules*. If we use the word "rules", we suggest that somebody created the rules first and then spoke the language, like a new game. But languages did not start like that. Languages started by people making sounds which evolved into words, phrases and sentences. No commonly-spoken language is fixed. All languages change over time. What we call "grammar" is simply a reflection of a language at a particular time.
Definition - Adjectives are words that describe nouns or pronouns. They may come before the word they describe (That is a cute puppy.) or they may follow the word they describe (That puppy is cute.).
Definition - Adverbs are words that modify everything but nouns and pronouns. They modify adjectives, verbs, and other adverbs. A word is an adverb if it answers how, when, or where.
The only adverbs that cause grammatical problems are those that answer the question how, so focus on these.
Examples:
He speaks slowly. Answers the question how.
He speaks very slowly. Answers the question how slowly.
Rule 1.
Generally, if a word answers the question how, it is an adverb. If it can have an -ly added to it, place it there.
Examples:
She thinks slow/slowly. She thinks how? slowly.
She is a slow/slowly thinker. Slow does not answer how, so no -ly is attached. Slow is an adjective here.
She thinks fast/fastly. Fast answers the question how, so it is an adverb. But fast never has an -ly attached to it.
We performed bad/badly. Badly describes how we performed.
Use the he/him method to decide which word is correct. he = who him = whom
Examples:
Who/Whom wrote the letter? He wrote the letter. Therefore, who is correct.
For who/whom should I vote? Should I vote for him? Therefore, whom is correct.
We all know who/whom pulled that prank. This sentence contains two clauses: We all know and who/whom pulled that prank. We are interested in the second clause because it contains the who/whom. Hepulled that prank. Therefore, who is correct. (Are you starting to sound like a hooting owl yet?)
We want to know on who/whom the prank was pulled. This sentence contains two clauses: We want to know and the prank was pulled on who/whom. Again, we are interested in the second clause because it contains the who/whom. The prank was pulled on him. Therefore, whom is correct.