Giáo viên dạy tiếng Việt.

It follows the very common Vietnamese pattern:

• Giáo viên = subject
• dạy = verb
• tiếng Việt = object

So the sentence is Subject + Verb + Object, just like English:

• Teacher teaches Vietnamese

That makes this sentence structurally quite friendly for English speakers.

Vietnamese usually does not require articles like a, an, or the.

So giáo viên can mean:

• a teacher
• the teacher
• sometimes even teachers in a general sense

The exact meaning depends on context.

If you want to be more specific, Vietnamese can add words such as:

• một giáo viên = a teacher / one teacher
• người giáo viên đó or more naturally giáo viên đó = that teacher
• các giáo viên = teachers

In your sentence, the bare noun giáo viên is perfectly normal.

By itself, giáo viên is not clearly marked for singular or plural.

Depending on context, it could mean:

• a teacher
• the teacher
• teachers as a general category

Vietnamese nouns usually do not change form for plural the way English nouns often do.

If you want to make plurality clearer, you can say:

• các giáo viên = teachers
• những giáo viên = teachers

If you want to make singular clearer, you can say:

• một giáo viên = one / a teacher

No. Giáo viên is gender-neutral.

It can refer to:

• a male teacher
• a female teacher

If gender matters, Vietnamese can add extra words, for example:

• giáo viên nam = male teacher
• giáo viên nữ = female teacher

One useful note: although giáo viên means teacher, Vietnamese speakers often address teachers as:

• thầy = male teacher
• cô = female teacher

So giáo viên is a noun for talking about a teacher, but not usually the most natural way to call one directly.

Dạy means to teach.

In this sentence, it is the main verb and works by itself just fine:

• Giáo viên dạy tiếng Việt = The teacher teaches Vietnamese

Vietnamese verbs do not need a special to form like English infinitives. The dictionary form is generally the same form used in sentences.

So:

• dạy = teach / teaches / teaching, depending on context

Other examples:

• Cô ấy dạy tiếng Anh = She teaches English
• Anh ấy dạy toán = He teaches math

Because tiếng Việt is the normal way to say Vietnamese language.

Here, tiếng can mean:

• language
• speech
• voice
• sound

In language names, tiếng + name is very common:

• tiếng Anh = English
• tiếng Pháp = French
• tiếng Nhật = Japanese
• tiếng Việt = Vietnamese

So Việt by itself is not normally how you say the language in this kind of sentence.
The full phrase tiếng Việt is the natural choice.

Because Việt is a proper name element, while giáo viên and tiếng are ordinary common words.

So:

• giáo viên = common noun
• dạy = verb
• tiếng = common noun
• Việt = proper name element related to Vietnam / Vietnamese

Vietnamese capitalization is generally lighter than English capitalization. You do not capitalize common nouns just because they are important words in the sentence.

Not explicitly.

Vietnamese verbs do not change form the way English verbs do.
So dạy can mean:

• teaches
• is teaching
• taught
• will teach

The time is usually understood from context or from extra time words.

For example:

• Giáo viên đang dạy tiếng Việt = The teacher is teaching Vietnamese
• Giáo viên đã dạy tiếng Việt = The teacher taught / has taught Vietnamese
• Giáo viên sẽ dạy tiếng Việt = The teacher will teach Vietnamese

Without those markers, Giáo viên dạy tiếng Việt is often understood as a simple present or a general statement.

To make it negative, add không before the verb:

• Giáo viên không dạy tiếng Việt = The teacher does not teach Vietnamese

To ask a yes/no question, a very common pattern is có ... không around the verb:

• Giáo viên có dạy tiếng Việt không? = Does the teacher teach Vietnamese?

In casual speech, people may also use a sentence-final particle:

• Giáo viên dạy tiếng Việt à? = The teacher teaches Vietnamese?
• Giáo viên dạy tiếng Việt hả? = same idea, casual

A rough guide:

• giáo viên → roughly zow vee-en in Northern Vietnamese, often closer to yow vee-en in Southern speech
• dạy → roughly yai or zai with a short, heavy, cut-off tone depending on accent
• tiếng Việt → roughly tee-ung vyet with tones

A few important points:

• Vietnamese is a tonal language, so the tone matters a lot.
• giáo has a rising tone.
• viên is level.
• dạy has a heavy, low tone.
• tiếng has a rising tone.
• Việt has a heavy, low tone.

English-style approximations are only rough. If possible, it is best to listen to a native speaker or audio recording and imitate the rhythm and tones.

Yes, absolutely.

It is short, but it is a complete and natural sentence:

• subject: giáo viên
• verb: dạy
• object: tiếng Việt

Vietnamese often allows very compact sentences, especially when context already makes things clear. So even though it may feel a little bare to an English speaker, it is perfectly normal.