Forbidden vs What you're asking is illegal

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

Forbidden

FormalTop 3,000 (common)

What you're asking is illegal

Beyond 10,000 (less common)
Most formal: ForbiddenMost common: Forbidden
 ForbiddenWhat you're asking is illegal
Pronunciation🇬🇧 //fəˈbɪd.ən//🇺🇸 //fərˈbɪd.ən//🇬🇧 //wɒt jʊə(r) ˈɑːskɪŋ ɪz ɪˈliːɡəl//🇺🇸 //wʌt jʊr ˈæskɪŋ ɪz ɪˈliɡəl//
MeaningNot allowed or banned.What you're asking is against the law.
ExampleThe secret room was strictly forbidden to anyone except the owner.What you're asking is illegal and could lead to serious consequences.
RegisterFormalNeutral
How commonTop 3,000 (common)Beyond 10,000 (less common)
Collocationsforbidden zone, forbidden love, forbidden activities, forbidden fruit, forbidden cityask about legality, illegal activities, illegal actions, illegal behavior, illegal trade
Antonymsallowed, permitted, legal-
Common mistakesConfused with 'prohibited' - both mean similar things, but 'forbidden' is less formal., Incorrectly used as a verb - 'forbidden' is strictly an adjective., Using 'forbidden' in positive contexts - it always suggests something disallowed.Using 'illicit' incorrectly instead of 'illegal'., Confusing legal terms with general vocabulary., Neglecting to clarify what is illegal.
Usage notesUsed to describe something that is legally or socially unacceptable. Avoid using in casual conversations.Use in formal situations, especially in legal contexts. Avoid casual conversations.

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Forbidden
What you're asking is illegal

Frequently asked questions: Forbidden vs What you're asking is illegal

What's the difference between Forbidden and What you're asking is illegal?

Forbidden: Not allowed or banned. What you're asking is illegal: What you're asking is against the law.

Which is more formal: Forbidden and What you're asking is illegal?

Forbidden is the most formal of these.

Which is more common: Forbidden and What you're asking is illegal?

Forbidden is the most common in everyday English.

Can you show an example of each?

Forbidden: The secret room was strictly forbidden to anyone except the owner. What you're asking is illegal: What you're asking is illegal and could lead to serious consequences.

Can I use Forbidden and What you're asking is illegal interchangeably?

Not always. Forbidden and What you're asking is illegal 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.