It is imperative vs Necessary

When to use each in English, with meaning, register, and examples.

It is imperative

Formal Top 2,000 (common)

Necessary

Top 1,000 (very common) A2 adjective

Most formal: It is imperative Most common: Necessary

	It is imperative	Necessary
Pronunciation	🇬🇧 //ɪt ɪz ɪmˈpɛrətɪv// 🇺🇸 //ɪt ɪz ɪmˈpɛrətɪv//	🇬🇧 /["/ˈnesəsəri/"]/ 🇺🇸 /["/ˈnesəseri/"]/
Meaning	It is very important or necessary.	Something that must be done or is very important.
Example	It is imperative that we submit the report by the deadline.	It is necessary to drink water to stay hydrated.
Register	Formal	Neutral
How common	Top 2,000 (common)	Top 1,000 (very common)
CEFR level	-	A2
Part of speech		adjective
Collocations	it is imperative to, it is imperative that, it is absolutely imperative, it is critical and imperative, it is considered imperative	appear, be, prove, really, strictly, absolutely, for, if necessary, as necessary, when necessary
Antonyms	-	unnecessary, optional, nonessential
Common mistakes	Using in casual contexts where simpler phrases work better., Confusing with 'it's important', which is less urgent.	Confused with 'necessity' — 'necessary' describes something needed, whereas 'necessity' is a noun., Using 'necessary' with an incorrect verb form — remember it usually pairs with 'to' before a verb., Omitting 'to' before the verb when using it in a phrase.
Usage notes	Use in formal writing or speeches to emphasize the necessity of an action. Avoid in casual conversations.	Used in both spoken and written language. Appropriate in academic and everyday contexts, but not overly casual. Avoid using it in informal conversations where simpler words like 'needed' might fit better.

See it in real clips

Agatha Christies Poirot › S1 E1

Now, it is imperative

It is imperative

It's a necessary risk.

Strippin' off those bloody rags is absolutely necessary.

Is this necessary?

It's a necessary risk.

Strippin' off those bloody rags is absolutely necessary.

Necessary

Frequently asked questions: It is imperative vs Necessary

What's the difference between It is imperative and Necessary?

It is imperative: It is very important or necessary. Necessary: Something that must be done or is very important.

Which is more formal: It is imperative and Necessary?

It is imperative is the most formal of these.

Which is more common: It is imperative and Necessary?

Necessary is the most common in everyday English.

Can you show an example of each?

It is imperative: It is imperative that we submit the report by the deadline. Necessary: It is necessary to drink water to stay hydrated.

Can I use It is imperative and Necessary interchangeably?

Not always. It is imperative and Necessary are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.