which must be

USAGE SUMMARY

The phrase "which must be" is correct and usable in written English.
It can be used to indicate a necessity or requirement related to a subject previously mentioned. Example: "The documents must be submitted by Friday, which must be adhered to strictly to avoid penalties."

✓ Grammatically correct

News & Media

Science

Formal & Business

Human-verified examples from authoritative sources

Exact Expressions

60 human-written examples

Which must be a relief.

The Guardian - Opinion

Which must be symbolic of something.

The New Yorker

Films are fantasies which must be read.

The Guardian - Film

It is Powell's side which must be held to account.

The Guardian - Opinion

It's about 6 30, which must be a busy period.

The New York Times

And then I complain about it, which must be boring".

The New Yorker

Which must be what William Bennett is getting at.

The New Yorker

"This is a political crisis which must be solved politically".

The Guardian - Business

Tickets (which must be purchased in advance): $150.

The New York Times

That is the bullet which must be bitten.

The Guardian - Sport

These pose an important problem, which must be solved.

The New Yorker

Expert writing Tips

Best practice

Use "which must be" to connect a nonrestrictive clause to a main clause, adding essential but non-defining information. This ensures clarity and logical flow in your writing.

Common error

Avoid using "that must be" when "which must be" is more appropriate. "That" introduces restrictive clauses that are essential to the sentence's meaning, while "which" introduces nonrestrictive clauses that add extra information. Misusing them can alter the intended meaning.

Linguistic Context

The phrase "which must be" functions as a relative clause introducing additional, non-essential information about a noun or pronoun. As Ludwig AI suggests, it indicates necessity or requirement linked to the preceding subject.

Expression frequency: Very common

Frequent in

Science

30%

News & Media

27%

Formal & Business

15%

Less common in

Wiki

8%

Encyclopedias

5%

Reference

5%

Ludwig's WRAP-UP

In summary, "which must be" is a versatile phrase used to introduce nonrestrictive clauses that add extra information or context to a sentence. As Ludwig AI confirms, it's grammatically correct and widely used. Its frequency across diverse sources, including science, news, and formal business contexts, makes it a valuable tool for clear and effective communication. Remember to distinguish its function from "that must be" to avoid grammatical errors. The examples in Ludwig highlight the phrase's adaptability and reliability in various writing scenarios.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

that has to be

Indicates obligation or requirement; more direct.

that by definition has to be

Emphasizes that the requirement is based on the definition of something.

that is required to be

Highlights the necessity based on specific requirements.

that is essentially

Indicates the basic and necessary nature of something.

that is logically required to be

Highlights the need based on logical reasoning.

that necessarily is

Emphasizes inevitability, making it a stronger assertion.

that is indispensably

Emphasizes the crucial nature of something, that it cannot be dispensed with.

that inevitably will be

Focuses on the certainty of future occurrence or state.

what inherently comprises

Highlights that something is an intrinsic part of something else.

what is unconditionally

Emphasizes the lack of conditions, highlighting absolute nature.

FAQs

How to use "which must be" in a sentence?

Use "which must be" to introduce a nonrestrictive clause that provides additional, non-essential information about something. For example, "The report, "which must be" submitted by Friday, contains critical data."

What can I say instead of "which must be"?

Alternatives include phrases like "that is required to be", "that has to be", or "that necessarily is", depending on the specific nuance you want to convey. Choose the alternative that best fits the context and maintains clarity.

Is it ever correct to use "that must be" instead of "which must be"?

While "which must be" introduces nonrestrictive clauses providing extra information, "that must be" would introduce a restrictive clause essential to the sentence's meaning. So, "that must be" is suitable only if the clause it introduces is essential to identifying the subject. Otherwise, stick with "which must be".

What's the difference between "which must be" and "that is required"?

"Which must be" often implies a sense of logical necessity or inherent quality, while "that is required" suggests a mandated or imposed necessity. The choice depends on whether the necessity arises from the nature of the subject or an external requirement.