How to distinguish the usage of the leading words of that and what clauses? for instance

The usage differences between that and what in noun clauses

1.。 That-led noun clause

First of all, the connecting pronouns that can be omitted when leading the first object clause and other nominal clauses cannot be omitted. For example:

It is

The rules require you not to tell anyone your password.

Your email account.

②-Don't

Do you think it necessary for him to go home at once?

-But the problem is.

No car.

③ Yes.

Bill is likely to recover in time to take part in the competition.

④ Our English

The teacher told us that we all did well in the exam.

We got full marks.

In the above four sentences, that leads the subject clause, predicative clause, appositive clause and object clause respectively, except the first that in the fourth example.

Can be omitted, others can not be omitted.

Secondly, when a noun clause is introduced, that does not constitute any component in the sentence. For example:

No one

I believe that the reason why he is absent from class is that he must meet his requirements.

Uncle at the airport.

In this sentence, that leads to appositive clauses, but it does not constitute any component of the sentence.

It's ours.

I believe that the improvement of medical care will bring more strength and more

Prosperous

Economy.

In this sentence, it is the formal subject, the subject clause guided by that is the real subject of the whole sentence, and that does not constitute any component in the sentence.

Finally, when a noun clause is introduced, it has no lexical meaning.

1) warm

It suddenly occurred to me that I could buy some with pocket money.

Flowers for my mother.

birthday

② Danbizuo

Tell my secretary that he will call again this afternoon.

In the above two examples, that only plays the role of guiding appositive clauses and has no lexical meaning.

To sum up, that has three characteristics in leading noun clauses: it can't be omitted, it doesn't make components, and it doesn't make sense.

2.What-guided noun clauses

First of all, when what leads to a noun clause, nothing is omitted from the sentence.

This usage is different from the usage when it introduces noun clauses.

He spoke.

He talked proudly about his role in the game, but didn't mention what his teammates had.

It's done.

What leads to the object clause in this sentence and what can't be omitted.

② Great.

That school has changed. It is no longer what it was 20 years ago.

Before, when it was poor.

Fully equipped.

What introduces predicative clauses in this sentence, but it cannot be omitted in the sentence.

Secondly, the things that lead to noun clauses have lexical meanings.

This is one of the important differences between what and that leading noun clauses. What does it generally mean "something/thing/person/time/place, etc." . For example:

Do you have any?

Do you know what happened?

Classroom?

What guides this appositive clause is the subject of this appositive clause, which means "something, something". The Chinese meaning of the whole sentence is "You know what happened in the classroom".

② What is it?

That's what you did, not what you said

It matters a lot.

This is an emphasized sentence pattern, and the emphasized part is two subject clauses guided by what. What in the sentence means "something, something", and the Chinese meaning of the whole sentence means "it depends on what you do, not what you say"

Finally, what not only plays a guiding role in guiding noun clauses, but also acts as a syntactic component in sentences.

This is the key to guide the difference between what and that in noun clauses.

I just

I wonder what makes him so excited.

A.b. What did he do?

C. What is it like? D. What is it

The correct answer to this question is D, which is a typical example of emphasizing that sentence patterns are objects. The emphasis component "what" not only plays the role of guiding the object clause in the sentence, but also acts as the subject of makes in the object clause.

② Modern

The city, which was a wasteland ten years ago, has been established.

In this sentence, the clause guided by what is the object of the preposition in, and at the same time, what is the subject of the object clause, which means "the position of …". It is worth noting that when introducing noun clauses, the sentences guided by that are generally not used as prepositional objects. On the contrary, sentences guided by what are more common as prepositional objects. For example:

③ Others.

One day, my brother was driving in the street, which I thought was dangerous.

Speed.

In this question, the preposition at is followed by an object clause guided by what. What is the subject in the object clause, but that cannot be used like this.

To sum up, what in leading noun clauses has three characteristics: it cannot be omitted, it is a component and meaningful.