toiawasemadoguti ni renrakusi tara dou desu ka.

問い合わせ窓口 is a compound noun meaning something like inquiry desk, contact point, customer support desk, or help desk, depending on context.

It breaks down like this:

• 問い合わせ = inquiry, question, contact
• 窓口 = literally window/counter, but often used figuratively for a service desk or point of contact

So together, it refers to the place, department, or contact channel you should reach out to.

The particle に marks the target of the contact.

With 連絡する, Japanese often uses:

• A に 連絡する = contact A

So:

• 問い合わせ窓口に連絡する = contact the inquiry desk / contact customer support

In English we might say contact customer service, but in Japanese the person or organization being contacted is often marked with に.

Because this is part of the たら form:

• 連絡する → 連絡したら

This comes from the past form:

• 連絡した
  • ら → 連絡したら

So the sentence is built from:

• 問い合わせ窓口に連絡したらどうですか

The し is just the stem you see before adding the rest of the conjugation.

V-たらどうですか is a very common pattern for making a suggestion.

It means:

• How about doing ... ?
• Why don’t you ... ?
• You could try ...

So:

• 問い合わせ窓口に連絡したらどうですか。 = Why don’t you contact the inquiry desk?

Even though たら often means if/when, in this pattern the whole phrase functions as a suggestion.

Good question. The た in たら comes from the past form, but たら itself is a conditional form, not simple past tense.

So 連絡したら here does not mean contacted in the past. It means something more like:

• if you contact
• if you were to contact
• why not contact

In other words, the form is historically based on the past, but its function here is grammatical, not truly past in meaning.

Yes, どうですか is polite. It makes the suggestion softer than a direct command.

Compare:

• 連絡してください。 = Please contact them.
• 連絡したらどうですか。 = Why don’t you contact them?

The second one sounds more like advice or a recommendation.

That said, whether it is appropriate depends on who you are speaking to. It is fine in many everyday situations, but when speaking to someone of much higher status, a more refined expression may be used.

Yes, the subject is omitted, which is very normal in Japanese.

The sentence naturally implies:

• you should contact the inquiry desk
• why don’t you contact the inquiry desk?

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

So even though you does not appear, the listener is understood to be the one who should take the action.

Sometimes you may see へ with things involving direction, but with 連絡する, に is the most standard choice.

• 問い合わせ窓口に連絡する = the normal phrasing

Using へ would sound less natural here for many learners’ purposes. If you want the safest pattern, use に with 連絡する.

Yes. Standard Japanese is normally written without spaces.

So the natural written form is:

問い合わせ窓口に連絡したらどうですか。

The spaces are often added only in teaching materials to make the structure easier for learners to see.

Yes. A casual version would be:

問い合わせ窓口に連絡したらどう？

This drops ですか, making it more informal.

Very roughly:

• 連絡したらどうですか。 = polite
• 連絡したらどう？ = casual

Both mean Why don’t you contact the inquiry desk?

In many real-world situations, yes. お問い合わせ窓口 is a more polite version and is very common in business, websites, forms, and customer service contexts.

• 問い合わせ窓口 = inquiry desk / contact desk
• お問い合わせ窓口 = more polite, more formal-sounding inquiry desk

The お adds politeness. Both are understandable, but お問い合わせ窓口 is especially common in formal customer-facing language.

It is grammatically a question, but functionally it is usually giving advice or making a suggestion.

So the speaker is not usually asking Is it good or bad to contact them? in a literal sense. Instead, they are suggesting:

• I think contacting the inquiry desk would be a good idea.

This is a very common Japanese way to make advice sound softer and less direct.