估计 / 可能
gūjì / kěnéng
Similarities
Both 估计 and 可能 express an inference based on the situation or the information available.
今天的工作估计完不成了，因为出了点儿问题。
We probably won't finish today's work — a small problem came up.
今天的工作可能完不成了，因为出了点儿问题。
We may not finish today's work — a small problem came up.
Either word works in this sentence.
1. 估计 is a verb, 可能 a modal verb
估计 + Clause
可能 + Verb
明天就可以上网查成绩了，我估计这次考试考得不错。
We can check the results online tomorrow. I reckon I did well this time.
明天就可以上网查成绩了，我这次考试可能考得不错。
We can check the results online tomorrow. I may have done well this time.
估计 can serve as the predicate itself and take a whole clause after it.
可能 normally sits in front of the main verb.
2. 可能 can also be an adjective
他这么多天没来上课，最可能的原因就是他回国了。
He hasn't been to class for days. The most likely reason is that he's gone home.
As an adjective 可能 means “possible”, “likely”. 估计 cannot be used this way.
3. 很可能
很可能他还不知道这件事。
He very likely still doesn't know about this.
他很可能还不知道这件事。
He most likely still doesn't know about this.
可能 takes 很 in front of it: 很可能. 很估计 is simply wrong.
Which one when?
我估计他已经到了。
I reckon he's already arrived.
他可能已经到了。
He may have already arrived.
| 估计 | 可能 |
|---|---|
| A verb | A modal verb or an adjective |
| Can introduce a whole clause | Sits before the verb |
| The speaker's estimate | The likelihood of an event |
| 很估计 ❌ | 很可能 ✅ |
Remember:
估计 = to reckon, I'd say.
可能 = may, possibly.
很可能 is very common; 很估计 is incorrect.