Learn Hardcore Japanese: huyu ha masuku nasi de soto ni deru to, kaze wo hiku kamo siremasen. - In winter, if you go outside without a mask, you might catch a cold.

Using 冬は adds a soft contrast or highlighting: in winter (as opposed to other seasons), if you go out without a mask, you might catch a cold. Japanese often uses は with seasons and times when they are the main “frame” of what you’re talking about.

What exactly does マスクなしで mean, and why not something like マスクをしないで?

マスクなしで literally means “with no mask / in a state of having no mask, and then…”.

Breakdown:

マスク = mask
なし = without, none
で = “with / in the state of / using” (marks the manner or condition)

So マスクなしで外に出る = “to go out in the condition of having no mask”.

You could also say:

マスクをしないで外に出る
マスクをつけないで外に出る

Both mean roughly “to go out without wearing a mask”.

Nuance:

マスクなしで → focuses on the state (mask = absent). Short, casual-sounding, very natural.
マスクをしないで / つけないで → focuses more on the action of not wearing it.

All are correct; マスクなしで is just compact and common.

What is the role of で in マスクなしで?

Here で marks the manner/condition in which the action happens:

マスクなしで外に出る
= “to go out with no mask / in a mask-less state.”

This is the same で you see in:

バスで行く – go by bus (by means of)
一人で行く – go alone (in the condition of being alone)
靴で部屋に入る – enter the room with shoes on (in that state)

So XなしでV is “to do V without X (in the state of not having X)”.

Why is it 外に出る and not 外へ出る or something with を?

The verb 出る (“to go out / to exit / to come out”) often takes に or へ for the destination:

外に出る – go out to the outside
外へ出る – go out toward the outside

In everyday speech, 外に出る is very natural and common. に here marks the place you end up at (the outside).

There is also another pattern:

部屋を出る – literally “to exit the room”
Here 部屋を marks the place you are leaving.

So:

Xを出る = exit X
Xに/へ出る = go out to/toward X

In this sentence, the focus is going out to outside, so 外に出る fits perfectly.

What does the と after 出る mean? Is it the same と as in “and”?

Here と is a conditional particle, not the simple “and”.

In 外に出ると、風邪をひくかもしれません, it means:

“When / if you go outside (under those conditions), you might catch a cold.”

This と often expresses a natural or typical result:

春になると、暖かくなります。
When it becomes spring, it gets warm.
ボタンを押すと、ドアが開きます。
If/when you press the button, the door opens.

So Vると、… → “when/if V happens, … (naturally follows).”

You could also use たら:

外に出たら、風邪をひくかもしれません。

Both are understandable, but Vると sounds more like a regular tendency or “whenever that happens, this tends to follow,” which matches the idea of “In winter, if you go out without a mask, (you tend to) catch a cold.”

What does the phrase 風邪をひく literally mean?

風邪をひく is the standard expression in Japanese for “to catch a cold.”

Breakdown:

風邪 (かぜ) – a cold (the illness)
を – marks the direct object
ひく (引く) – literally “to pull / to draw,” but in this set phrase it doesn’t feel like “pull” anymore.

So it’s like “to pull in a cold” → “to catch a cold”.

You almost always say:

風邪をひく – catch a cold
(often written 風邪を引く with the kanji)

You generally don’t say things like:

✕ 風邪がある (“have a cold” – unnatural)
✕ 風邪になる for “catch a cold” (sounds weird for this meaning)

If you mean “have a cold (right now)”, you’d still say:

風邪をひいています。 – I have a cold. (lit. I am in the state of having caught a cold.)

What does かもしれません mean exactly? How strong is it?

かもしれません means “might / may / it’s possible that …” and expresses uncertainty.

In this sentence:

風邪をひくかもしれません。
→ You might catch a cold. / There’s a possibility you’ll catch a cold.

Nuance of probability:

It’s like saying “maybe” or “might”; you’re not sure at all.
It does not sound like a strong prediction. It’s softer than “You probably will.”

Structure:

Attach かもしれません to the plain form of a verb/adjective:
- 行くかもしれません – might go
- 寒いかもしれません – it might be cold
- 学生かもしれません – he/she might be a student

Casual form:

かもしれない (plain)
かも by itself in casual speech:
- 風邪ひくかも。 – Might catch a cold.

Why is it かも「しれません」 and not something with 知りません?

かもしれません comes from かも + 知れる (potential form of 知る) + ません (polite negative):

知れる → “can be known”
知れません → “cannot be known” (polite negative potential)

So very literally, かもしれません is like:

“Even this (かも) cannot be known.” → “It’s not knowable whether it’s so or not.” → “It might (be).”

Important points:

It is a fixed expression. You must say かもしれません, かもしれない, or かも.
You cannot say:
- ✕ かもしりません
- ✕ かも知りません (with り)
You may occasionally see the kanji:
- かも知れません / かも知れない, but they are read the same as かもしれません / かもしれない.

Is 風邪をひくかもしれません polite, casual, or neutral?

風邪をひくかもしれません uses ます-form (しれません), so it is polite.

Polite:
- 風邪をひくかもしれません。
Plain/casual:
- 風邪をひくかもしれない。
- Even more casual: 風邪ひくかも。

In normal everyday conversation with strangers, teachers, coworkers, etc., かもしれません is safe and appropriate. With friends or family, かもしれない or just かも is common.

Could I say 冬にマスクなしで外に出たら、風邪をひくかもしれません instead? What changes?

Yes, you can say:

冬にマスクなしで外に出たら、風邪をひくかもしれません。

Main differences:

冬は → 冬に
- 冬は: topic; gives a slight contrast “as for winter…”
- 冬に: simple time expression “in winter”.
出ると → 出たら
- Vると: “when(ever) V happens, (typically) … follows.” Tends to sound more like a general tendency or automatic result.
- Vたら: “if/when V happens, then …” – more general conditional, often more event-like, sometimes more one-time-sounding.

So the original:

冬はマスクなしで外に出ると、風邪をひくかもしれません。
→ “In winter, if you (generally / whenever you) go out without a mask, you might catch a cold.”

The たら version sounds a bit more like a specific scenario, but both are grammatically correct and natural.

Can I change the word order, like 冬は外にマスクなしで出ると?

You have some flexibility, but not everything sounds equally natural.

Original:
冬はマスクなしで外に出ると、風邪をひくかもしれません。
(Very natural.)
冬は外にマスクなしで出ると、風邪をひくかもしれません。
This is understandable, but sounds a bit awkward. Native speakers normally keep マスクなしで right before 出る, since it directly modifies the manner of “going out.”

Much better reorderings would be like:

冬は外にマスクなしで出ると… ✕ (odd)
冬は外に出るとき、マスクなしだと… → Here the structure changes, but it’s natural.

General guideline: keep マスクなしで close to the verb it modifies (出る), and don’t separate 外に and 出る too much without a good reason.

Could I drop some particles in casual speech, like 冬マスクなしで外出ると?

In casual spoken Japanese, some particles can be dropped, especially は, を, and sometimes に, as long as the meaning is clear.

For example, in very casual speech you might hear something like:

冬マスクなしで外出ると、風邪ひくかも。

Changes:

冬は → 冬 (drop は)
外に出る → 外出る (drop に)
風邪をひく → 風邪ひく (drop を)
かもしれません → かも (casual)

This sounds like something a friend might say.

However:

For learning and for polite/neutral written Japanese, keeping the particles as in the original sentence is best:
- 冬はマスクなしで外に出ると、風邪をひくかもしれません。