Meaning & Usage
When you aren't 100% sure about a fact or a future event, you use かもしれない (kamoshirenai). In English, we usually translate this as "might," "maybe," or "it’s possible that." It represents a subjective guess where the speaker is speculating. In terms of probability, it usually indicates a 50% chance or lower. It feels much less certain than でしょう (deshou), which suggests you are fairly confident in your prediction.
The phrase has an interesting literal origin. It combines the particle か (question), も (also/even), and 知れない (cannot know). Essentially, you are saying "one cannot even know if it is [X] or not." This creates a humble, indirect tone. Japanese speakers often use this to avoid sounding too assertive or aggressive when giving an opinion.
You will encounter three main levels of formality with this grammar. かもしれません (kamoshiremasen) is the polite version used in work or with strangers. かもしれない (kamoshirenai) is the standard plain form. In casual conversation, friends often shorten it to just かも (kamo).
Structure & Formation
The most important rule for かもしれない is how it connects to nouns and adjectives. Unlike other grammar points, it usually attaches directly to the word without extra particles.
| Word Type | Rule | Example |
|---|---|---|
| Verbs | Plain Form (Any Tense) | 行く + かもしれない |
| Nouns | Direct (No "da") | 先生 + かもしれない |
| い-Adjectives | Dictionary Form | 寒い + かもしれない |
| な-Adjectives | Stem (No "na", No "da") | 静か + かもしれない |
Watch out for the Noun and な-adjective categories. You must never use the copula だ (da) before かもしれない. Beginners often mistakenly say "ame da kamoshirenai." The correct form is simply "ame kamoshirenai."
Example Sentences
1. Weather and Predictions
明日は雨が降るかもしれない。
ashita wa ame ga furu kamoshirenai.
It might rain tomorrow.
午後から雪になるかもしれません。
gogo kara yuki ni naru kamoshiremasen.
It might turn to snow in the afternoon.
2. Health and Physical State
風邪を引いたのかもしれない。
kaze wo hiita no kamoshirenai.
I might have caught a cold.
彼は今日、体調が悪いのかもしれません。
kare wa kyou, taichou ga warui no kamoshiremasen.
He might be feeling unwell today.
3. Daily Life and Plans
道が混んでいるので、遅れるかもしれない。
michi ga konde iru node, okureru kamoshirenai.
The roads are crowded, so I might be late.
鍵を車の中に忘れたかもしれない！
kagi wo kuruma no naka ni wasureta kamoshirenai!
I might have forgotten my keys in the car!
4. Speculating about Others
この料理は彼には辛すぎるかもしれない。
kono ryouri wa kare ni wa karasugiru kamoshirenai.
This dish might be too spicy for him.
彼はまだそのニュースを知らないかもしれない。
kare wa mada sono nyuusu wo shiranai kamoshirenai.
He might not know that news yet.
5. Casual Conversational "Kamo"
このケーキ、おいしいかも！
kono keeki, oishii kamo!
This cake might actually be good!
来週のパーティー、行けるかも。
raishuu no paatii, ikeru kamo.
I might be able to go to next week's party.
Common Mistakes
Mistake 1: Using "da" with Nouns
❌ 病気だかもしれない。
✅ 病気かもしれない。
This is the most frequent error for N4 students. Unlike phrases like と言いました, you do not use the copula だ here. Connect the noun directly to かもしれない.
Mistake 2: Confusing with ~hazu
❌ 明日は日曜日だから、銀行は休みかもしれない。
✅ 明日は日曜日だから、銀行は休みのはずだ。
Use かもしれない for guesses with low certainty. If there is a logical reason to expect something (like a calendar), use はず (hazu) instead. かもしれない implies you are truly unsure.
Cultural Notes
In Japan, maintaining social harmony (和) is vital. Direct refusals can sound harsh. Because of this, speakers often use かもしれない as a polite softener. If a boss says, "That plan might be difficult," they are often politely saying it's impossible. Pay attention to the context to see if it's a genuine guess or a polite "no."
In text messages, the short form かも is incredibly common. It adds a soft, non-committal tone to your sentences. However, avoid using かも with teachers or superiors. It sounds very informal and can even come across as slightly childish in a professional setting.
Related Grammar Points
- Hearsay (I heard that): Souda (Grammar N4)
- The Grammar of Appearance: Using ～そうだ (Grammar N4)
- Don't Have To / No Need To (Grammar N4)
- Understanding はずだ: Expressing Logical Expectations (Grammar N4)
- Sequence and Starting Points: Using てから (te kara) (Grammar N4)
- Resultant State (Intentional) - Te-aru (Grammar N4)
JLPT Tips
On the N4 exam, かもしれない often appears in the grammar section to test the "No だ" rule. Look closely at the choices for nouns and na-adjectives. If you see a choice with だ or な right before かもしれない, it is almost certainly a trap.
In the listening section, listen for the falling intonation at the end of the phrase. If a speaker ends with かもしれません, they are expressing doubt. This usually means the answer to the question is not a definite "yes." Finally, remember that the past tense is かもしれなかった (might have been). While less common at N4, it can appear in reading passages.