Đây là mật khẩu Wi-Fi.

Word by word:

• đây = this / here
• là = is / am / are in an identifying or equational sentence
• mật khẩu = password
• Wi-Fi = Wi-Fi

So the structure is basically:

• Đây là X = This is X

Both can relate to this, but they do different jobs.

• đây usually works as this / here and can stand on its own.
• này usually comes after a noun and means this.

So:

• Đây là mật khẩu Wi-Fi. = This is the Wi-Fi password.
• Mật khẩu Wi-Fi này... = this Wi-Fi password...

A helpful way to remember it:

• đây = points to something by itself
• này = attaches to a noun

Là links two things together, like is in English when you are identifying something.

In Đây là mật khẩu Wi‑Fi:

• đây = this
• mật khẩu Wi‑Fi = the Wi‑Fi password
• là connects them: This is the Wi‑Fi password

It is natural and expected here. Without là, the sentence would sound incomplete or unnatural in standard Vietnamese.

It is written as two separate syllables, but together they form one lexical item, meaning password.

This is very common in Vietnamese. Many words are made of two syllables written separately:

• mật khẩu = password
• điện thoại = telephone
• máy tính = computer

So when learning Vietnamese, do not assume that spaces always separate fully independent words in the same way they do in English.

Vietnamese usually puts the main noun first, then the word that specifies what kind it is.

So:

• mật khẩu Wi‑Fi = Wi‑Fi password
  • main noun: mật khẩu = password
  • specifying element: Wi‑Fi

This is very common:

• cà phê sữa = milk coffee
• áo sơ mi trắng = white dress shirt

English often puts modifiers before the noun, but Vietnamese often puts them after.

A rough pronunciation guide for English speakers:

• Đây ≈ day but with a Vietnamese vowel, not exactly English day
• là ≈ lah
• mật ≈ muht with a short, clipped ending
• khẩu ≈ something like khow with breathy kh
• Wi‑Fi is usually pronounced close to the English term, though often with Vietnamese rhythm

Important sound notes:

• đ is like a normal English d
• kh is like a strong breathy k sound, somewhat like the ch in German Bach or Scottish loch, but often easier for learners to approximate as an aspirated k
• final -t in mật is unreleased: your tongue closes, but you do not strongly release the sound

The tones are:

• đây: level tone with the ây vowel combination
• là: low falling tone
• mật: heavy/glottalized low tone
• khẩu: dipping-rising tone

Tones matter a lot in Vietnamese. For example:

• mật khẩu = password
• changing the tones could create a different word or something unintelligible

If you are just starting, it is often helpful to learn the sentence in chunks:

• Đây là...
• mật khẩu
• Wi‑Fi

Then practice the full sentence.

Vietnamese does not use articles like a, an, and the in the same way English does.

So mật khẩu Wi‑Fi can mean:

• a Wi‑Fi password
• the Wi‑Fi password

The exact meaning depends on context.

In Đây là mật khẩu Wi‑Fi, the context usually makes it mean This is the Wi‑Fi password.

Usually, no. That would sound odd in normal speech.

The classifier cái is used with many objects, but abstract things like mật khẩu normally do not need it here.

Natural:

• Đây là mật khẩu Wi‑Fi.

Less natural / odd in this context:

• Đây là cái mật khẩu Wi‑Fi.

For learners, the safest choice is simply mật khẩu.

Yes, if the context already makes it clear what password you mean.

• Đây là mật khẩu. = This is the password.
• Đây là mật khẩu Wi‑Fi. = This is the Wi‑Fi password.

Adding Wi‑Fi makes it more specific.

Wi‑Fi is very commonly used in Vietnamese exactly in that form. It is a normal borrowed term.

People also commonly say things like:

• mật khẩu Wi‑Fi
• bắt Wi‑Fi = get/connect to Wi‑Fi
• Wi‑Fi yếu = weak Wi‑Fi

So using Wi‑Fi here is completely natural.

Yes, slightly.

• Đây là mật khẩu Wi‑Fi. = This is the Wi‑Fi password.
• Đó là mật khẩu Wi‑Fi. = That is the Wi‑Fi password.

So the difference is mainly this versus that.

Use đây when the thing is near you or you are presenting it directly. Use đó when it is farther away or already being referred to.

You can add a polite particle at the end, depending on the situation.

For example:

• Đây là mật khẩu Wi‑Fi ạ.

The ạ makes the sentence more polite and respectful, especially when speaking to a customer, guest, older person, or someone of higher status.

Without ạ, the sentence is still correct. With ạ, it sounds softer and more polite.

Yes, absolutely. It is very natural in that situation.

For example, if you hand someone a card or point to a paper, you can say:

• Đây là mật khẩu Wi‑Fi.

It works well when:

• showing a written password
• pointing to a sign
• presenting the password on a phone screen

So it is a very practical everyday sentence.