Saying what might happen: "might", "could", "there is a risk"
かもしれない is the everyday "might", for good news and bad alike, and the one to start with. Most of the other forms are commoner in the news, on notices and in formal writing than in conversation. Two of them are for something bad: one is your own warning, and the other is an official announcement.
| Form | What it says | Where |
|---|---|---|
| かもしれない, かも | "Might", "maybe": possible, but you wouldn't bet on it | Everyday; かも with friends |
| ありえる, ありえない | "It could happen"; "impossible", "unbelievable" | Conversation |
| かねない | "Might well": a warning that something bad could follow | News, warnings |
| おそれがある | "There is a risk that": the official way to say something bad may happen | Forecasts, official notices, labels |
| 可能性がある | "There is a possibility": good or bad, with no warning in it | News, reports, business; conversation too |
| 得る, 得ない | Can, or cannot, happen in principle | Essays, reports, textbooks |
かもしれない: might, maybe
Full pageかもしれないN4
You say かもしれない when you can't say yes and you can't say no. It works for your own plans too, when nothing is decided.
There may still be some tickets left.
Maybe we've taken the wrong road.
もしかしたら, "possibly", often goes with it.
I might go to Hokkaido during summer vacation.
With friends it shrinks to かも, as in そうかも.
Isn't this the wrong road?
You might be right.
People also say it when they are fairly sure, to soften a disagreement or bad news.
That may be so, but I like this one better.
Sorry, I might be a little late.
Where it goes wrong
English speakers reach for たぶん to say "maybe". たぶん is "probably": you think it likely. When it could go either way, it is かもしれない.
I'll probably go to tomorrow's party.
The host can expect you.
I might go to tomorrow's party.
The host can't count on you.
ありえる and ありえない: could happen, impossible
Full page得る・
Everyone says ありえる, "it could happen", and ありえない, "impossible". Both are about whether a thing is possible at all; a guess about one case is かもしれない. ありえない is also "unbelievable", said in shock or protest.
Could a coincidence like that really happen?
Making people wait a whole hour? Unbelievable.
かねない: might well
Full pageかねないN2
かねない is your own warning that a situation or an action could lead to something bad. It is often a criticism of whoever is letting it happen. It follows a verb stem.
If the situation is left unattended, the damage could spread further.
At this rate, we may end up missing the deadline.
I wouldn't put it past him.
Said about a person, it is a verdict on their character.
It is not usually said of something you hope for.
Not said: 頑張れば、
(If you work hard, you might well pass the exam.)
合格できるかもしれない.
おそれがある: there is a risk that
Full pageおそれがあるN2
おそれがある is how forecasts, the news and official notices say that something bad may happen. It announces a risk, and the wording itself blames no one. It is also written 恐れがある.
There is a risk of heavy rain from tonight through tomorrow morning.
The personal information of about 3,000 people may have been leaked.
After a past form it is "may have".
Between people it sounds like a public announcement.
Sounds odd: 明日の
There is a risk that I will be slightly late for tomorrow's party.
To a friend: 少し遅れるかもしれない.
かもしれない, かねない or おそれがある?
All three say that an operation on a computer could erase data. What differs is who is talking.
This operation might erase the data.
One colleague to another, not sure either way.
This operation could erase data that has already been saved.
Your own warning that the operation is dangerous, as a review of the software might put it.
This operation may result in the loss of saved data.
The manual, or the message on the screen.
可能性がある: there is a possibility
Full page可能性がある・
可能性がある is said of good and bad alike. かもしれない is your own guess; 可能性がある sounds worked out from the facts, and it can say how likely, which かもしれない can't. 可能性が高い is "likely", and 可能性が低い, "unlikely".
Depending on how hard you work, you may even reach your goal in six months.
With も in place of が: "may even".
Heavy snow has continued since last night. Therefore, the afternoon flights are likely to be canceled too.
得る・得ない: possible in principle
Full page得る・
On a verb stem, 得る says that something can happen or be so in principle, and 得ない that it cannot. ありえる and ありえない are ある with these endings; on other verbs the endings belong to writing.
A major earthquake can happen anywhere, at any time.
得る is read うる, the standard reading, or える, which is common in conversation. 得ない is always えない.
These factors alone cannot account for this change.
得る or かねない?
Where かねない warns, 得る only states that a thing is possible.
A small input error can lead to a serious accident.
As a report would put it.
Speeding could well lead to a serious accident.
A warning to anyone who drives too fast.
Other things "may", "can" and "cannot" mean
ことがあるN3
The "may" of notices and labels: it happens now and then. A guess about one occasion is かもしれない.
While I am away on business, my replies may be delayed.
The "can" of skill and ability. 得る is not said of a skill.
I can speak Japanese.
かねるN2
"Cannot": how staff politely refuse a customer. かねない is made as its negative, but the two are used as separate expressions.
We are unable to accommodate your request.
Surer than "might"
でしょう・だろうN5
"Probably": you think it likely. In conversation people usually say たぶん…と思う.
Tomorrow it will probably start raining in the afternoon.