komatta toki ha, kangosisan wo yonde kudasai.

Because 困った is modifying とき.

In Japanese, verbs can directly modify nouns.

• 困る = to be troubled / to be in trouble
• 困ったとき = when you are in trouble / when a problem comes up

Even though 困った is the past form, in a phrase like this it does not necessarily mean past time in English. It often means something like when you have gotten into trouble or when a problem has happened.

So 困ったとき is a very natural way to say when you’re in trouble.

とき means time or when.

So:

• 困ったとき = when you are in trouble

The は after it marks that whole phrase as the topic:

• 困ったときは、... = As for when you’re in trouble, ... / When you’re in trouble, ...

In natural English, we usually just translate it as when.

The は can also add a slight sense of in that situation or at times like that.

They are similar, but the nuance is different.

• 困ったとき = when you have gotten into trouble / when something problematic has happened
• 困るとき = when you are troubled / at times when you have trouble

In many cases, 困ったとき sounds more natural for instructions like this, because it refers to a situation that comes up and then you should do something.

So in a hospital or care setting, 困ったときは、看護師さんを呼んでください sounds very natural.

さん is an honorific, used to be polite and respectful.

• 看護師 = nurse
• 看護師さん = nurse, with a polite/respectful tone

In English, we usually do not translate さん directly. It does not mean exactly Mr. or Ms. here. It just makes the sentence sound kinder and more polite.

In places like hospitals, schools, or stores, Japanese often adds さん when referring to staff members in a friendly or respectful way.

No. 看護師 is gender-neutral.

It can refer to:

• a male nurse
• a female nurse
• any nurse regardless of gender

This is the standard modern term. Older terms like 看護婦 were gender-specific and are now generally avoided in standard usage.

Because 呼ぶ takes a direct object.

• 呼ぶ = to call
• 看護師さんを呼ぶ = to call the nurse

So を marks the person being called.

This is different from English, where we just say call the nurse without a visible object marker.

呼んでください is:

• 呼ぶ → dictionary form, to call
• 呼んで → te-form
• ください → please

So:

• 呼んでください = please call

This is a standard polite request pattern:

• Vてください = please do V

Examples:

• 待ってください = please wait
• 見てください = please look
• 呼んでください = please call

Also, note the form change:

• 呼ぶ → 呼んで This is a normal te-form conjugation pattern for -ぶ verbs.

Japanese often leaves out subjects when they are obvious from context.

Here, the sentence is giving an instruction to the listener, so you is understood:

• 困ったときは、看護師さんを呼んでください。
• When you’re in trouble, please call the nurse.

Adding あなたは would usually sound unnecessary, and sometimes even unnatural, unless there is special emphasis.

It is a polite instruction/request.

Vてください usually means:

• please do ...

Depending on context, it can sound like:

• a polite request
• an instruction
• guidance
• a rule

In a hospital setting, this sentence would likely be understood as a polite instruction:
If you need help, please call a nurse.

It is softer than a plain command like 呼んで or 呼びなさい.

No, the comma is not strictly necessary.

You could write:

• 困ったときは看護師さんを呼んでください。

The comma simply helps show a pause after the topic phrase:

• 困ったときは、...

Japanese punctuation is often more flexible than English punctuation, especially in simple sentences like this.

Yes, 困った is broad and depends on context.

It can mean things like:

• you need help
• you do not know what to do
• something is wrong
• you are having difficulty
• a problem has come up

In a hospital or care context, it often means:

• if you need assistance
• if something is wrong
• if you are having trouble

So the exact nuance comes from the situation, not just from the word 困った itself.

A helpful breakdown is:

• 困った = were troubled / got into trouble
• とき = time / when
• は = topic marker
• 看護師さん = nurse
• を = object marker
• 呼んで = call, in te-form
• ください = please

So very literally:

• As for when you are in trouble, please call the nurse.

A more natural English translation is:

• If you need help, please call a nurse.
• When you’re in trouble, please call the nurse.