If you do the usage of whether or not, try to be as accurate as possible, thank you 5

if is used to express the meaning of "whether", and the corresponding tense needs to be determined according to the meaning of the sentence, and the simple future tense can be used after if; If is not placed at the beginning of a sentence, only after the verb, etc. In addition to the meaning of "if", if can also be used to express the meaning of "if".

if is used to express the meaning of "if": in denoting a situation that may arise in the future, the if clause replaces the simple future tense with the simple present tense, the simple future tense cannot appear after if, and the main clause uses the simple future tense, i.e., the so-called "subject will be from the present" (the main clause is in the simple future tense, and the clause is in the simple present tense). If should be placed at the beginning of the sentence, before the main clause, separated from the subject by a comma; It is placed after the main clause and does not have to be a comma before if.

if is an English word, noun, conjunction, which when used as a noun means "condition, conceive; uncertain situation", when used as a conjunction, means "(table condition) if; (Table assumptions) if, if; Whenever; Although, even if; (for indirect doubts) whether; (for courtesy inquiries) whether; When, every time; (in conjunction with modal verbs) is tactful and polite; It's not ......, if it is ......How nice; Probably not; Even if; Although".

1. If as a conjunction, it can also lead to an object clause, which means whether or not.

The guiding object clause has the same meaning as whether.

For example: lily asked if whether she liked it

Lily asks her if she likes it.

Second, if can also guide the concession adverbial clause. In this case, if is taken as "even if", "although it is".

For example: if she's poor, at least she's honest

Although she was poor, at least she was honest.

3. If guides the time adverbial clause, when if is interpreted as "when" or "when" without the meaning of the condition, the tense in the if clause is the same as the tense in the main clause.

For example: if youmix yellow and blue, you get green

If you mix yellow with blue, you get green.

Fourth, if is used in conjunction with some other prepositions.

As is used in conjunction with if, and it means: "as if, as if" also guides the clause.

For example: it isn't as if we are rich (we are not rich).

We don't look like rich. (i.e. we are not rich).

Fifth, as if can also lead exclamation sentences.

For example: as if i would allow it!

As if I would say yes!