ame no hi ha, kutu ga kitanai mama da to, heya no yuka mo yogoremasu.

A natural breakdown is:

• 雨の日は = as for rainy days / on rainy days
• 靴が = shoes
• 汚いままだと = if they stay dirty / if they are left dirty
• 部屋の床も = the room’s floor too
• 汚れます = gets dirty

So the structure is basically:

• On rainy days, if your shoes are still dirty, the floor in the room gets dirty too.

A more literal feel is:

• As for rainy days, if shoes are in the state of being dirty, the room’s floor also becomes dirty.

Here, の links two nouns:

• 雨 = rain
• 日 = day

So 雨の日 means a rainy day or more literally a day of rain.

This is a very common noun-linking use of の:

• 日本の車 = Japanese car / car of Japan
• 学校の先生 = school teacher / teacher of the school
• 雨の日 = rainy day / day of rain

So 雨の日 is just a set expression meaning rainy day.

は marks the topic, while に often marks a specific time when something happens.

Here, 雨の日は means something like:

• as for rainy days
• on rainy days
• when it’s a rainy day

The sentence is making a general statement about rainy days, not describing one specific event. That is why は feels natural.

Compare:

• 雨の日は、靴が汚れやすいです。
  = On rainy days, shoes get dirty easily.
  (general statement)

• 雨の日に、出かけました。
  = I went out on a rainy day.
  (specific action happening at that time)

So は helps set the scene as a topic: speaking of rainy days...

Here, 靴が汚い describes the condition the shoes are dirty. In this kind of clause, が often marks the thing that has the property or state.

So:

• 靴が汚い = the shoes are dirty

If you used 靴は, it would sound more like you are contrasting the shoes with something else:

• 靴は汚い = the shoes are dirty
  (maybe implying something else is not, or shifting topic to the shoes)

In this sentence, 雨の日は is already the main topic. Inside that bigger statement, 靴が is simply the subject of 汚い.

So the structure is:

• [雨の日は] = main topic
• [靴が汚いままだと] = conditional clause

まま means remaining as it is, left in that state, or without changing.

So:

• 汚い = dirty
• 汚いまま = still dirty / left dirty / remaining dirty

In this sentence, 靴が汚いまま means:

• the shoes stay dirty
• the shoes are left dirty
• the shoes remain dirty

This まま pattern is very common:

• ドアを開けたまま = leaving the door open
• 靴を履いたまま = still wearing shoes
• 何もしないまま = without doing anything

So the feeling here is not just dirty, but dirty and not cleaned before going into the room.

This is a very common learner question.

Even though 汚い is an い-adjective, the だ is not attaching directly to 汚い. It is attaching to まま as part of the conditional pattern X だと.

You can think of it like this:

• 汚いまま = being in the state of remaining dirty
• 汚いままだ = it is in that unchanged dirty state
• 汚いままだと = if it is in that unchanged dirty state

So the だ belongs to the whole まま expression before と.

This is similar to how noun-like expressions often take だ before と.

A useful way to remember it:

• まま often behaves like a state expression that can be followed by だ, especially in patterns like ままだ, ままだと, etc.

Yes. Here と is the conditional meaning if / when.

So:

• 靴が汚いままだと = if the shoes stay dirty
• more literally: when shoes are left dirty, ...

The conditional と is often used when the result is:

• natural
• automatic
• habitual
• generally true

That fits this sentence well:

• If you leave dirty shoes on a rainy day, the floor gets dirty too.

It sounds like a general consequence.

Compare the nuance with other conditionals:

• 〜と = if/when, natural consequence
• 〜たら = if/when, very flexible, often used for specific situations
• 〜なら = if/as for, based on a condition or assumption
• 〜ば = formal/logical if

Here と is a good choice because the sentence describes a typical result.

Because the sentence is talking about becoming dirty, not just being dirty.

• 汚い = dirty (a state)
• 汚れる = to get dirty / to become dirty

So:

• 床が汚いです = the floor is dirty
• 床が汚れます = the floor gets dirty

In this sentence, the floor is not necessarily dirty at first. The meaning is that it ends up becoming dirty because of the dirty shoes.

That is why 汚れます is the better choice here.

Yes, 靴が汚れたままだと would also be possible, but the nuance is slightly different.

• 汚い = dirty, unclean, in a dirty state
• 汚れた = got dirty / dirtied; a resulting state from becoming dirty

So:

• 靴が汚いままだと focuses on the shoes being dirty
• 靴が汚れたままだと focuses a bit more on the shoes having become dirty and being left that way

In many everyday situations, both can work.

This sentence uses 汚いまま because it straightforwardly describes the shoes as dirty. It feels simple and natural.

も means also / too.

So:

• 部屋の床も汚れます = the room’s floor gets dirty too

The idea is:

• the shoes are dirty
• and the floor too becomes dirty

So も adds the sense of in addition.

Without も, the sentence would still make sense:

• 部屋の床が汚れます = the room’s floor gets dirty

But も helps show the relationship:

• not only are the shoes dirty,
• the floor also gets dirty.

Yes. 部屋の床 literally means:

• 部屋 = room
• 床 = floor
• 部屋の床 = the room’s floor / the floor in the room

This is another normal noun + の + noun pattern.

In English, we often just say the floor if the location is obvious. In Japanese, adding 部屋の can make it clearer that we mean the indoor floor, not outside ground or some other surface.

Japanese often puts the topic or setting near the beginning.

So:

• 雨の日は、... sets the scene first: on rainy days...

That makes the sentence easy to follow because the listener immediately knows the context.

Other word orders are sometimes possible in Japanese, but this one is very natural because it goes from:

1. setting/topic: rainy days
2. condition: if the shoes stay dirty
3. result: the room’s floor also gets dirty

That order is very common in explanatory or general statements.

The comma is mainly there to make the sentence easier to read.

Since 雨の日は is the topic phrase and the rest of the sentence is a longer condition-plus-result structure, the comma helps separate the parts:

• 雨の日は、
• 靴が汚いままだと、
• 部屋の床も汚れます。

Japanese commas are often used more flexibly than English commas. They are not always strictly required, but they can improve clarity and rhythm.

Here, the commas help show:

• the topic
• the conditional clause
• the main result

Yes, in natural English we might translate it as your shoes and your room, but Japanese often leaves that kind of information unstated when it is obvious from context.

So:

• 靴 can mean shoes
• 部屋 can mean room

Depending on context, the listener understands whose shoes and whose room are meant.

Japanese frequently omits:

• my
• your
• his/her
• even the subject of the sentence

if they are already clear from the situation.

So the sentence does not need to say あなたの靴 or あなたの部屋 unless there is a reason to emphasize ownership.