With regards to describing a person who just can't stop thinking about something. The Cambridge Advanced Learner's Dictionary (3rd Edition) defines these words as follows:

obsessed: unable to stop thinking about something; too interested in or worried about something

obsessive: thinking about something or someone, or doing something, too much or all the time

I am not seeing the difference here. Am I obsessed about learning the exact recognition of the English phonemes, or am I obsessive about that? Should I say You are being obsessed or You are being obsessive when someone is overreacting because they are thinking too much?

  • What is still unclear about your question?
    – user66974
    Oct 19, 2016 at 7:36
  • I just want more different opinions on it, hence the label "This question has not received enough attention." Oct 19, 2016 at 7:58
  • +1 Not just because it's a good question but for the irony of obsessing over a question about being obsessive/obsessed.
    – Dog Lover
    Oct 20, 2016 at 3:39
  • Lol, dude, I'm totally with you. Oct 20, 2016 at 11:08
  • 1
    obsessed is a condition of being... obsessive is a potential of becoming... Oct 23, 2016 at 1:31

3 Answers 3


Cambridge may have oversimplified the matter somewhat. The difference is in the suffixes, which both operated upon the root word obsess.

obsess To excessively preoccupy the thoughts or feelings of; to haunt the mind persistently. 1

-ive An adjective suffix signifying relating or belonging to of the nature of tending to; as, affirmative, active, conclusive, corrective, diminutive .1

-ed The termination of the past participle of regular, or weak, verbs; also, of analogous participial adjectives from nouns; as, pigmented; talented.1

Thus the word obsessive relates more narrowly to the tendency to frequently think a certain thought or feel a certain way.

The -ed suffix is a little more complicated as it acts as a past participle.

Participle (Gram) A part of speech partaking of the nature of both verb and adjective; a form of a verb, or verbal adjective, modifying a noun, but taking the adjuncts of the verb from which it is derived. In the sentences: a letter is written; being asleep he did not hear; exhausted by toil he will sleep soundly,written being, and exhausted are participles.1

Since participles have the partial nature of a verb, it indicates some sort of action which implies an agent to cause the action. This is not so different so far but participles often denote an ongoing state of action, and past participles in particular further note that this state has at the least already began, if it has not yet also subsisted too.

Hence obsessed indicates that there is obsession occurring within a certain period of time. This places emphasis on an act of obsession itself and its actual cause, rather than having the latent ability to become obsessed or potential to cause obsession like the word obsessive does.

1 Webster's Revised Unabridged Dictionary 1913

  • @Tonepoet So obsessive=under obsession by nature; in general/generically. obsessed=under a single obsession in a particular situation. Pardon me but I'm tryna reinterpret what you're saying in simpler term to see if I actually comprehend it. Oct 17, 2016 at 6:35
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    Also, I should say, "He has obsessive behaviors", "He's an obsessive type", "He acts obsessively"; but "He's obsessed about getting his projects done", correct? Oct 17, 2016 at 6:39
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    @Vun-HughVaw That's the gist of it in my opinion, although you may want to see what the other members say about it. Also those examples seem fine, pendent upon the context.
    – Tonepoet
    Oct 17, 2016 at 6:54
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    I'd say "he's obsessed about getting his projects done" if his behavior is specific to his current projects, or if I am only talking about his current projects; if he always acts obsessed about any project and I am commenting on that, I'd say "he's obsessive about getting his projects done."
    – Hellion
    Oct 17, 2016 at 15:14
  • "The -ed suffix is a little more complicated as it acts as a past participle.... Since participles have the partial nature of a verb, it indicates some sort of action which implies an agent to cause the action." I'm certainly not going to disagree, but this nuance adds complexity which may not be necessary here. Let us simply call the past participle here an adjective and focus on how the suffixes themselves impart different subtexts. I think that such an approach would be more intuitive for an English learner.
    – scottb
    Oct 17, 2016 at 15:32

I will try to give you a more intuitive, less theoretical grasp of the difference. Think of possessive and possessed. I think they are easier to distinguish, but they could give you a useful model to hang your hat on.

The character in the horror movie was possessed by an alien creature.

Small children can be quite possessive about their personal belongings. It can be helpful to prepare for a visit from a young friend by inviting your child to put certain key personal items in a closet before the friend arrives.

When you're obsessed about something, it is almost as though you were taken over by an alien creature.

When you are obsessive about something, you have a certain tendency. That is also a bit like the child who's possessive about his things. ("Mine, mine, mine!")

  • I think Aparente's answer is a lot more useful than all the rest together, and OP Vun-Hugh Vaw's secondary questions for clarification illustrate a very swift understanding. Nov 1, 2016 at 23:58
  • @RobbieGoodwin - glad you liked the answer. Care to vote? My intuitive answer is still at zero.... Nov 2, 2016 at 3:55

There seems to be some over-complication attributed to this.

"Obsessive" has its roots as a psychiatric word, involving both anxiety and mental disorders. Its use in common speech stems from this beginning, but it still maintains a medical/clinical connotation.

Most obsessive tendencies can be traced back to childhood events or traumas.
Do you think ironing my jeans makes me look obsessive?
His love of movies tends toward the obsessive. (He goes to the cinema 365 days a year.)
You're obsessive about the lives of celebrities. (I don't want to say stalker...)

"Obsessed" is just the past participle adjective construction of "obsess". As such it implies preoccupation and fixation.

I am obsessed with cat photos on the Internet.
Obsessed with the new trilogy, he barely looked up from his books all week.
He seems obsessed with movies. (And chooses to quote them far too often.)
You're obsessed about the lives of celebrities. (Weird, but not clinically weird.)

You are, I hope, only obsessed with the recognition of English phonemes. Unless you get the grammar shakes...just one more etymology, man...I'm good for it...

  • @RobbieGoodwin I don't really understand the intent of your question. If you're asking if "obsess" can be used as a participle adjective, then yes. "I will be obsessed with my book all morning. Please do not disturb."
    – Cord
    Nov 13, 2016 at 15:54

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