think of vs think about (Murphy Unit 134, Verb + preposition 3)
Pattern
Section titled “Pattern”-
think of = an idea occurs to you / recall / consider briefly
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think about = contemplate / mull over deeply
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Why didn’t I think of that? ✓ (the idea should have come to mind)
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I’m thinking about your offer. (considering deeply)
The two meanings
Section titled “The two meanings”| think of | think about | |
|---|---|---|
| Meaning | idea comes to mind, recall | contemplate, ponder |
| Depth | brief, sudden | deeper, longer |
| Example | think of a name | think about the future |
| Indonesian | terpikir | memikirkan (deeply) |
Context clue: “Why didn’t I think of that?” = the idea should have occurred to me → of (sudden idea).
Other “think of” uses
Section titled “Other “think of” uses”- What do you think of this? = your opinion (of)
- think of you = remember / care about you
- I can’t think of her name. = recall
Test application
Section titled “Test application”What a good idea! Why didn’t I think ___ that?
Answer: of — the fixed idiom “think of that” (the idea should have come to mind).
Why not “about”? — “think about that” would mean “ponder that matter deeply” — odd for a sudden realization. The idiom for ideas is “think of”.
Test application 2 (excuse)
Section titled “Test application 2 (excuse)”I don’t want to go out with Tom tonight. I’ll have to think ___ an excuse.
Answer: of — invent/produce an excuse (the excuse doesn’t exist yet; you must come up with it).
Why not “about”? — “think about an excuse” = mull over an excuse that already exists. The frame needs producing one → of.
Rule of thumb: of = product, about = process. Idea/excuse doesn’t exist → of (come up with it). Already on your mind, weighing it → about.
Source
Section titled “Source”Raymond Murphy, English Grammar in Use (4th ed.), Unit 134 — Verb + preposition 3. Ebot lesson 2026-08-29: “Why didn’t I think ___ that?” → of (idea comes to mind).