Completion vs Realization

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

Completion

Top 2,000 (common)B2noun

Realization

Top 2,000 (common)C1noun
 CompletionRealization
Pronunciation🇬🇧 /["/kəmˈpliːʃn/"]/🇺🇸 /["/kəmˈpliːʃn/"]/🇬🇧 /["/ˌriːəlaɪˈzeɪʃn//ˌrɪəlaɪˈzeɪʃn/"]/🇺🇸 /["/ˌriːələˈzeɪʃn/"]/
MeaningThe act of finishing something.Understanding something clearly or becoming aware of it.
ExampleThe completion of the project was celebrated with a party.As realization dawned, he went pale.
RegisterNeutralNeutral
How commonTop 2,000 (common)Top 2,000 (common)
CEFR levelB2C1
Part of speechnounnoun
Collocationsrapid, speedy, early, near, reach, bring something to, date, time, rate, after completion, following completion, before completion, the date of completionfull, dawning, growing, come to, come (to somebody), dawn (on somebody), hit somebody
Antonymsincompletion, unfinished, failureignorance, unawareness
Common mistakesUsing 'complete' instead of 'completion' as a noun, Confusing it with 'completionist' in game contexts, Saying 'the completion of the work is done' instead of 'the completion of the work is finished'Confused with 'realise' and 'realization' — remember 'realization' is a noun., Using 'realization' in formal writing where a simpler word like 'understanding' may be more appropriate., Mixing up with 'realistic' — they have different meanings.
Usage notesUse 'completion' in contexts where something is finished. Common in academic or formal settings, but less so in casual conversation. Be careful in using it in informal settings where simpler words may work better.Use 'realization' when someone suddenly understands or discovers something important. It's neutral and suitable for both spoken and written contexts, but avoid it in casual slang conversations.

Frequently asked questions: Completion vs Realization

What's the difference between Completion and Realization?

Completion: The act of finishing something. Realization: Understanding something clearly or becoming aware of it.

Which is more advanced: Completion and Realization?

Realization is the highest level, at C1, on the CEFR scale.

Are Completion and Realization the same CEFR level?

Completion: B2, Realization: C1 on the CEFR scale.

What part of speech are Completion and Realization?

Completion: noun, Realization: noun.

Can you show an example of each?

Completion: The completion of the project was celebrated with a party. Realization: As realization dawned, he went pale.

Can I use Completion and Realization interchangeably?

Not always. Completion and Realization 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.

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