ame no hi wa sentakumono ga zenzen kawakanai.

雨の日 literally means rain day, but more naturally it means a rainy day or days when it rains.

The particle の connects two nouns. Here it works like of or like a noun modifier:

• 雨 = rain
• 日 = day
• 雨の日 = day of rain / rainy day

This is a very common pattern in Japanese:

• 休みの日 = day off
• 夏の日 = summer day
• 日本の文化 = Japanese culture / the culture of Japan

The は marks 雨の日 as the topic of the sentence.

So the sentence is structured like:

• 雨の日は = as for rainy days / on rainy days
• 洗濯物が全然乾かない = the laundry does not dry at all

This は gives the sentence a general, contextual feeling:
When it’s a rainy day, the laundry doesn’t dry at all.

It can also carry a slight contrast, like:

• rainy days: laundry doesn’t dry
• other days: maybe it does

Because 乾く is an intransitive verb. It means to dry in the sense of become dry.

So the thing that becomes dry is marked with が, not を:

• 洗濯物が乾く = the laundry dries

If you use the transitive verb 乾かす instead, then you use を:

• 洗濯物を乾かす = dry the laundry

So:

• 乾く = something dries
• 乾かす = someone dries something

洗濯物 means laundry, especially clothes or other items being washed or dried.

It does not usually mean the act of doing laundry itself. It means the actual items:

• shirts
• towels
• socks
• bedding, etc.

So in this sentence, it refers to the laundry/clothes that are trying to dry.

Here, 全然 means not at all.

It is used with a negative form, so:

• 全然乾かない = does not dry at all

This is a very common pattern:

• 全然わからない = I don’t understand at all
• 全然できない = I can’t do it at all
• 全然大丈夫じゃない = it’s not okay at all

You may also hear 全然 with positive expressions in casual modern speech, but in this sentence it is the standard negative usage.

乾かない is the plain negative form of 乾く.

Conjugation:

• dictionary form: 乾く = dry / become dry
• negative: 乾かない = does not dry

This is a normal godan-verb change:

• 書く → 書かない
• 開く → 開かない
• 乾く → 乾かない

So the sentence is simply saying that the laundry doesn’t dry.

Because 乾かない and 乾けない are not exactly the same.

• 乾かない = does not dry
• 乾けない = cannot dry / is unable to dry

In this sentence, Japanese usually prefers 乾かない to describe what normally happens under these conditions. It sounds like an observation of reality:

On rainy days, the laundry just doesn’t dry.

Using 乾けない would focus more on impossibility/ability, which is not the most natural choice here.

The sentence ends in 乾かない, which is the plain form. Japanese often uses plain form in:

• textbooks
• dictionaries
• casual conversation
• general statements
• written explanations

The polite version would be:

雨の日は洗濯物が全然乾きません。

Both are correct. The plain form is just less formal.

Yes, but the nuance changes a little.

• 雨の日は = as for rainy days / on rainy days
  This sets up a general topic.
• 雨の日に = on a rainy day
  This sounds more like a time marker for a particular event or situation.

In this sentence, は is very natural because the speaker is making a general statement about rainy days.

You could also say:

雨の日には洗濯物が全然乾かない。

This adds に plus は, giving a slight emphasis/contrast: On rainy days, laundry really doesn’t dry.

Yes, but the nuance changes.

• 洗濯物が全然乾かない = the laundry doesn’t dry at all
  This presents laundry as the subject of the statement.
• 洗濯物は全然乾かない = as for the laundry, it doesn’t dry at all
  This makes laundry the topic.

In your sentence, 雨の日は is already the main topic, so using 洗濯物が is very natural:

• 雨の日は = topic/context
• 洗濯物が = subject within that context

You can say 雨の日は洗濯物は全然乾かない, but it sounds more contrastive or heavy, because you now have two は topics.

Usually it means rainy days in general.

Because the sentence is in the non-past form and uses は on 雨の日, it sounds like a general truth or habitual statement:

On rainy days, laundry doesn’t dry at all.

Depending on context, Japanese non-past can sometimes refer to a present or future situation, but without extra context this sentence is most naturally understood as a general statement.

Japanese word order is more flexible than English, but 全然 usually goes before the verb or before the part it modifies.

The given sentence is very natural:

雨の日は 洗濯物が 全然 乾かない。

You may also hear slight variations, such as:

• 雨の日は全然洗濯物が乾かない。
• 雨の日は洗濯物が乾かない、全然。
  (more conversational/emphatic)

But the original order is standard and easy to understand.

A useful way is:

• 雨の日は = on rainy days / as for rainy days
• 洗濯物が = the laundry
• 全然 = not at all
• 乾かない = does not dry

So the overall structure is:

[Topic] [Subject] [Adverb] [Verb]

This is a very common Japanese pattern, and learning to spot these chunks makes sentences much easier to read.