Immediately vs Suddenly

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

Immediately

Top 1,000 (very common)A2adverb

Suddenly

Top 1,000 (very common)A2adverb
 ImmediatelySuddenly
Pronunciation🇬🇧 /["/ɪˈmiːdiətli/"]/🇺🇸 /["/ɪˈmiːdiətli/"]/🇬🇧 /["/ˈsʌdənli/"]/🇺🇸 /["/ˈsʌdənli/"]/
Meaningright away, without waitingHappening quickly and without warning
ExampleHe answered the question immediately after it was asked.I **suddenly realized** what I had to do.
RegisterNeutralNeutral
How commonTop 1,000 (very common)Top 1,000 (very common)
CEFR levelA2A2
Part of speechadverbadverb
Collocationsrespond immediately, act immediately, notify immediatelysuddenly appear, suddenly realize, suddenly stop, suddenly change
Antonymseventually, latergradually, slowly
Common mistakesUsing 'immediate' instead of 'immediately'., Confusing with 'eventually', which means later., Incorrectly placing 'immediately' at the end of a sentence.Using 'suddenly' with the wrong tense (e.g., 'sudden' for past actions)., Confusing 'suddenly' with 'sudden', forgetting it needs to modify verbs., Using 'suddenly' too often, making writing sound repetitive.
Usage notesUse 'immediately' to emphasize urgency or promptness. It's appropriate in both spoken and written English, but avoid in very casual contexts.Use 'suddenly' to describe an unexpected change or event. Commonly used in storytelling or descriptions of surprising moments. Avoid in very formal contexts.

See it in real clips

Immediately
Suddenly

Frequently asked questions: Immediately vs Suddenly

What's the difference between Immediately and Suddenly?

Immediately: right away, without waiting Suddenly: Happening quickly and without warning

Are Immediately and Suddenly the same CEFR level?

Immediately: A2, Suddenly: A2 on the CEFR scale.

What part of speech are Immediately and Suddenly?

Immediately: adverb, Suddenly: adverb.

Can you show an example of each?

Immediately: He answered the question immediately after it was asked. Suddenly: I **suddenly realized** what I had to do.

Can I use Immediately and Suddenly interchangeably?

Not always. Immediately and Suddenly 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.