haru ni naru to, kahun de hana no tyousi ga warukute, kusyami ga yoku demasu.

春になると means something like when it becomes spring or once spring comes.

• 春になる = to become spring / for it to turn into spring
• と after a verb here means when or whenever, often for things that happen naturally or regularly

So 春になると、... sets up a recurring situation:

• When spring comes, ...
• Whenever it becomes spring, ...

This と is often used when the result is a natural consequence or something that regularly happens.

In 春になる, the particle に marks the state something changes into.

• なる = to become
• 春に = into spring / to spring

So:

• 春になる = to become spring → more naturally, it becomes spring / spring arrives

This is the same pattern as:

• 先生になる = become a teacher
• 元気になる = become healthy
• 静かになる = become quiet

Good question. These can all relate to when, but they are not identical.

In this sentence, 春になると sounds natural because it describes a habitual, repeated result:

• When spring comes, my nose gets bad and I sneeze a lot.

と often suggests:

• a regular pattern
• a natural consequence
• something that predictably happens

Compare:

• 春になると、花粉が増える。
  When spring comes, pollen increases.
  Natural, recurring fact.

• 春になったら、旅行します。
  When spring comes, I’ll travel.
  More like a plan or decision.

• 春のとき is not the same structure here. とき means at the time when, but 春になると is the more natural way to say when spring comes in this sentence.

Here, で means because of or due to.

• 花粉 = pollen
• 花粉で = because of pollen

So the sentence is saying the bad nose condition happens because of pollen.

This use of で can mark a cause, especially for:

• physical conditions
• temporary situations
• things happening as a result of something

Examples:

• 風邪で学校を休みました。
  I was absent from school because of a cold.
• 事故で電車が止まった。
  The train stopped because of an accident.

So 花粉で鼻の調子が悪くて means:

• My nose feels bad because of pollen
• Because of pollen, my nasal condition is bad

鼻の調子 literally means the condition of my nose.

• 鼻 = nose
• 調子 = condition, state, how something is functioning

So 鼻の調子が悪い means:

• my nose is not doing well
• my nose feels bad
• I’m having nasal problems

This is a very Japanese way of describing physical condition. English often says:

• My nose is bothering me
• My nose feels bad
• I’m having trouble with my nose

Japanese often uses Xの調子が悪い for the functioning or condition of something:

• 体の調子が悪い = I’m not feeling well
• パソコンの調子が悪い = my computer isn’t working well
• 喉の調子が悪い = my throat is in bad condition

The particle の links nouns together. Here it shows that 調子 belongs to or is related to 鼻.

• 鼻 = nose
• 調子 = condition
• 鼻の調子 = the nose’s condition / the condition of my nose

This is a very common noun-modifying pattern in Japanese:

• 日本の文化 = Japanese culture / the culture of Japan
• 学校の先生 = the school’s teacher / teacher at the school
• 目の痛み = pain in the eyes

So 鼻の調子 is just a natural noun phrase.

悪くて is the て-form of 悪い. Here it connects this clause to the next one.

• 鼻の調子が悪くて、くしゃみがよく出ます。
• My nose is in bad condition, and I sneeze a lot.
• It can also carry a slight because feeling: my nose is bad, so I sneeze a lot

So 悪くて is doing two jobs at once:

1. linking clauses
2. suggesting a reason/background

Compare:

• 悪いです。
  Just a complete statement: It is bad.

• 悪いので、くしゃみがよく出ます。
  More explicitly: Because it’s bad, I sneeze a lot.

• 悪くて、くしゃみがよく出ます。
  More natural and conversational in a sentence like this.

In 鼻の調子が悪い, the thing being described as bad is 鼻の調子, so it takes が.

• 鼻の調子が悪い = the condition of my nose is bad

This is a common pattern:

• 頭が痛い = my head hurts
• 気分が悪い = I feel sick
• 目がかゆい = my eyes are itchy

Even though English often uses my, Japanese often just marks the body part or condition with が.

In Japanese, くしゃみが出る is the natural expression for to sneeze.

Literally, it is like:

• a sneeze comes out

So:

• くしゃみが出ます = I sneeze / sneezes come out

Japanese often uses 出る for bodily things that come out or happen involuntarily:

• せきが出る = to cough
• 鼻水が出る = one’s nose runs / nasal discharge comes out
• 涙が出る = tears come out

くしゃみをする does exist, but くしゃみが出る often sounds more natural when the sneezing happens automatically because of a condition like pollen.

Here, よく means often or frequently, not well.

So:

• くしゃみがよく出ます = I sneeze a lot / I often sneeze

よく can mean different things depending on context:

1. well

   • 日本語がよくわかります。
     I understand Japanese well.

2. often

   • よく行きます。
     I go often.

In this sentence, because it is talking about sneezing frequency, よく clearly means often.

Because they belong to different parts of the sentence.

1. 鼻の調子が悪くて
   Here, が marks 鼻の調子 as the thing that is bad.

2. くしゃみがよく出ます
   Here, が marks くしゃみ as the thing that comes out.

So the sentence is really made of linked parts:

• When spring comes,
• because of pollen, my nose’s condition is bad,
• and sneezes come out often.

Japanese can have multiple が particles in one sentence as long as they belong to different clauses or predicates.

Japanese often leaves the subject unstated when it is obvious from context.

In English, you would probably say:

• When spring comes, because of pollen, my nose gets bad and I sneeze a lot.

But in Japanese, I is often omitted if the speaker is clearly talking about their own experience.

So the implied subject is usually:

• I / my or sometimes more generally
• people like me

This omission is completely normal in Japanese.

Yes, that is the natural implication.

Using と here gives the feeling of a repeated, typical event:

• Whenever spring comes, this happens.

So the sentence does not sound like a one-time event. It sounds like:

• This is my usual springtime problem.

If the speaker wanted to focus on just one particular future time, they might use something else, like たら.

Yes, but it would mean something slightly different.

• 花粉で = because of pollen
• 花粉症で = because of hay fever / pollen allergy

So:

• 花粉で鼻の調子が悪くて、くしゃみがよく出ます。
  Because of pollen, my nose feels bad and I sneeze a lot.

• 花粉症で鼻の調子が悪くて、くしゃみがよく出ます。
  Because of hay fever, my nose feels bad and I sneeze a lot.

Using 花粉で focuses on the cause as pollen itself.
Using 花粉症で focuses on the medical condition or allergy.

Yes, it sounds natural, though it is a little broad.

It can cover symptoms like:

• stuffy nose
• runny nose
• irritated nose
• general nasal discomfort

If you want to be more specific, Japanese also has more direct expressions such as:

• 鼻水が出ます = my nose runs
• 鼻がつまります = my nose gets clogged
• 鼻がむずむずします = my nose feels tickly/irritated

But 鼻の調子が悪い is a useful general expression for my nose isn’t in good shape.

Yes. That is one important thing about the て-form.

In 鼻の調子が悪くて、くしゃみがよく出ます, the て-form can feel like:

• and
• so
• because

In English, you might translate it as:

• My nose feels bad, and I sneeze a lot.
• My nose feels bad, so I sneeze a lot.
• Because my nose is irritated, I sneeze a lot.

The exact nuance depends on context, but in this sentence there is clearly a causal connection.

Because Japanese often describes physical experiences differently from English.

Instead of saying something like:

• When spring comes, pollen makes me sneeze a lot

Japanese naturally breaks it into conditions and symptoms:

• When spring comes, because of pollen, my nose’s condition gets bad, and sneezes come out often.

This kind of expression is very common in Japanese:

• state of body part
• cause marked with で
• symptom marked with が出る

So even if it feels indirect from an English perspective, it is very natural Japanese.