Obsessed With: Standard Pattern
Obsessed With: Standard Pattern records a directly documented English construction and keeps guidance bounded to the evidenced pattern rather than inventing a broader prohibition.
Use “obsessed with” when someone is unable to stop thinking about or is excessively interested in a person or thing.
Key details
Choose the right form
| Meaning / situation | Form / construction | Decision |
|---|---|---|
| unable to stop thinking about or excessively interested in a person or thing | obsessed with + noun/-ing phrase | Use the directly documented “with” construction. |
| same broad meaning with the documented alternative preposition | obsessed by + noun phrase | Recognize this alternative rather than calling it universally wrong. |
| ordinary strong interest described without the excessive/uncontrollable sense | interested in / enthusiastic about, as context requires | Choose a less intense expression when “obsessed” overstates the intended meaning. |
Quick tests
Meaning / construction test
Do you mean an excessive or hard-to-stop preoccupation with the person, thing, or activity?
If yes: Use “obsessed with” followed by the focus of that preoccupation.
If no: If the interest is ordinary rather than excessive, choose a milder expression; “obsessed by” is also documented as an alternative complement.
Caveat: Cambridge also records “obsessed by”; this guide documents the common “with” construction without turning it into an exclusive-preposition rule.
Examples
He became obsessed with solving the puzzle.
The “with” phrase identifies the focus of the excessive preoccupation.
She is obsessed with the tiny details of the design.
The complement names what occupies her attention excessively.
They are enthusiastic about local history.
A milder expression fits when the intended meaning is strong interest rather than obsession.
Further guidance
Construction
Use “obsessed with” when someone is unable to stop thinking about or is excessively interested in a person or thing.
Style Boundary
Cambridge also records “obsessed by”; this page does not present “with” as the only possible complement.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- OBSESSED WITH SOMEONE/SOMETHING - Cambridge English Dictionary (opens in a new tab)Cambridge University Press · Direct Cambridge learner-dictionary evidence for the obsessed with construction and its meaning boundary.