Ignorance vs What i don't know

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

Ignorance

Top 2,000 (common)C1noun

What i don't know

Top 3,000 (common)
Most common: Ignorance
 IgnoranceWhat i don't know
Pronunciation🇬🇧 /["/ˈɪɡnərəns/"]/🇺🇸 /["/ˈɪɡnərəns/"]/🇬🇧 //wɒt aɪ doʊnt noʊ//🇺🇸 //wɑt aɪ doʊnt noʊ//
MeaningNot knowing something or lacking information.Things I am not aware of.
ExampleThe danger of ignorance is that people often fail to recognize their own biases.I can't help you with that; it's just what I don't know.
RegisterNeutralNeutral
How commonTop 2,000 (common)Top 3,000 (common)
CEFR levelC1-
Part of speechnoun
Collocationscomplete, total, utter, betray, demonstrate, display, due to ignorance, in ignorance  (of), in your ignorancewhat I don't understand, what I don't remember, what I don't believe
Antonymsknowledge, awareness, understandingwhat I do know, knowledge, understanding
Common mistakesConfused with 'ignore' - Ignorance means lack of knowledge, not simply ignoring something., Using inappropriately in polite contexts - It's often seen as rude to call someone ignorant directly.Confused with 'what I do know'., Misused in affirmative sentences., Used incorrectly as a question.
Usage notesUsed to refer to a lack of knowledge or awareness. Can be formal in texts but is generally neutral. Not appropriate in polite conversation to describe someone's lack of knowledge directly.Use this phrase when expressing uncertainty or lack of knowledge. It's appropriate in both casual and formal conversations.

See it in real clips

Ignorance
What i don't know

Frequently asked questions: Ignorance vs What i don't know

What's the difference between Ignorance and What i don't know?

Ignorance: Not knowing something or lacking information. What i don't know: Things I am not aware of.

Which is more common: Ignorance and What i don't know?

Ignorance is the most common in everyday English.

Can you show an example of each?

Ignorance: The danger of ignorance is that people often fail to recognize their own biases. What i don't know: I can't help you with that; it's just what I don't know.

Can I use Ignorance and What i don't know interchangeably?

Not always. Ignorance and What i don't know 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.