Must is an adverb with emphasis and used as an adverbial.

"Must" is often confused with "necessity" in application. "Must" and "necessity" are synonyms, both of which have inevitable meanings. The difference is that the former emphasizes necessity, while the latter emphasizes necessity.

Identification of extended data words;

Must be necessary

1, the word "must" and the word "must" are homonyms, both of which have the meaning of "must" and are easily confused.

"must" is usually followed by a verb. It is compulsory to do sth.

3. "Necessary" is usually followed by a noun, which means that something especially needed is subjective and urgent, such as "necessities".

4. They are not interchangeable, but they overlap and have the same meaning in specific objects.

5, must: adverbs, with emphasis, mostly adverbials.

6. Express necessity and emphasize facts or necessity. For example, "You must be brave." "We must be modest and prudent and avoid jealousy."

(1) followed by a verb,

Secondly, adjectives. Sometimes it can also be used before clauses, such as: "If you want to make rapid progress, you must work together with Qi Xin."

7. Strengthen the tone of the command. For example, "You have to handle this alone." He must go to the hospital for a serious examination.

8. The negative form of "must" is "unnecessary, unnecessary, unnecessary."

Necessary: verb, indicating that there must be, indispensable. As an attribute or predicate.

For example, "as the price of raw materials necessary for production rises, the production cost is also rising." Air and water are necessary for everyone.

References:

Baidu Encyclopedia-Must? Discrimination of words