Lan mở bản đồ trên điện thoại và hỏi: “Tôi nên đi thẳng hay rẽ phải?”

Yes. Mở literally means open, and it is very commonly used for opening apps, maps, documents, websites, and similar things.

So Lan mở bản đồ trên điện thoại means Lan opens the map on her phone.

A few related verbs:

• mở = open
• đóng = close
• bật = turn on
• tắt = turn off

So:

• mở bản đồ = open the map
• bật điện thoại = turn on the phone

You would usually not say bật bản đồ if you mean opening the map app or map screen.

Vietnamese does not use articles like English a / an / the.

So:

• bản đồ can mean a map or the map
• điện thoại can mean a phone or the phone

The exact meaning depends on context.

In this sentence, mở bản đồ trên điện thoại is naturally understood as opening the map on the phone, even though Vietnamese does not mark definiteness the way English does.

Bản đồ is the normal noun meaning map.

Here:

• bản is not functioning as a normal classifier in this phrase
• bản đồ is a fixed vocabulary item meaning map

So you should learn bản đồ as one unit.

If you wanted to count maps, then a classifier may appear:

• một tấm bản đồ = one map

But in the original sentence, no classifier is needed because the speaker is just referring to the map / a map in general.

Here it means on the phone, in the sense of on the device / on the screen / on the phone itself.

Literally, trên often means on or above, but in modern usage it is also very common for digital contexts:

• trên điện thoại = on the phone
• trên máy tính = on the computer
• trên mạng = online / on the internet

So in this sentence, mở bản đồ trên điện thoại means opening the map on one’s phone, not physically placing a paper map on top of the phone.

Yes. và means and, and hỏi means ask.

So the structure is:

• Lan mở bản đồ trên điện thoại và hỏi
• Lan opens the map on her phone and asks

Vietnamese often links actions in a straightforward sequence like this without changing the verb form for tense. The time is understood from context.

Depending on context, this could be interpreted in English as:

• Lan opens the map on her phone and asks
• Lan opened the map on her phone and asked

Vietnamese verbs do not conjugate the way English verbs do.

In Vietnamese, the person being asked can be omitted if it is obvious or unimportant.

So hỏi by itself can simply mean asked.

If you wanted to include the person, you could say:

• hỏi tôi = ask me
• hỏi anh ấy = ask him
• hỏi đường = ask for directions

In this sentence, the focus is on the question she asks, not on who she asks.

Tôi is a neutral first-person pronoun meaning I.

It is very common in textbooks because it is safe and broadly usable. However, in real life, Vietnamese speakers often choose pronouns based on age, relationship, and situation.

Depending on context, someone might say:

• em nên đi thẳng hay rẽ phải?
• mình nên đi thẳng hay rẽ phải?
• con nên đi thẳng hay rẽ phải?

So tôi is grammatically correct, but in everyday speech it can sound more formal or neutral than what close friends or family would usually say.

Nên means should.

So:

• Tôi nên đi thẳng hay rẽ phải? = Should I go straight or turn right?

It is used for asking for advice or the best choice.

Compare:

• Tôi đi thẳng hay rẽ phải? = Do I go straight or turn right? / Should I go straight or turn right?
  This can work, but it is less explicit.
• Tôi nên đi thẳng hay rẽ phải? = Which is the better option for me?

So nên adds the idea of recommendation or guidance.

In this sentence, hay means or in a question offering alternatives.

• đi thẳng hay rẽ phải? = go straight or turn right?

This is very natural in Vietnamese when asking someone to choose between two possibilities.

By contrast, hoặc also means or, but it is more common in statements, formal language, or written lists.

A simple way to remember it:

• hay = often used in questions with choices
• hoặc = often used in statements

So here, hay is the natural choice.

Because đi thẳng is the full verb phrase meaning go straight.

• đi = go
• thẳng = straight

Similarly:

• rẽ phải = turn right
• rẽ trái = turn left

If you said only thẳng, it could work in certain very short spoken contexts, especially when giving directions, but đi thẳng is the full and clearer expression.

Examples:

• Cứ đi thẳng. = Just go straight.
• Đi thẳng rồi rẽ trái. = Go straight, then turn left.

No. In rẽ phải, phải means right as the direction.

This is a very common source of confusion because phải can also mean must / have to in other contexts.

Compare:

• rẽ phải = turn right
• bên phải = the right side
• Tôi phải đi. = I have to go.

So the meaning of phải depends on context. In this sentence, it clearly means the direction right.

The structure is:

• Tôi = I
• nên = should
• đi thẳng = go straight
• hay = or
• rẽ phải = turn right

So the order is basically:

subject + should + option 1 + or + option 2

This is quite similar to English:

• I should go straight or turn right?

But in natural English, we usually say:

• Should I go straight or turn right?

Vietnamese does not need to move nên to the front to form this kind of question.

Vietnamese often marks questions through context, question words, and punctuation rather than by changing word order.

Here, it is understood as a question because:

• there is a question mark: ?
• hay presents two alternatives
• the meaning naturally asks for a choice

So Vietnamese can keep the statement-like order and still be clearly interrogative.

You can use rẽ phải for walking, driving, biking, and moving in general.

It simply means turn right.

Examples:

• Đi bộ đến ngã tư rồi rẽ phải. = Walk to the intersection, then turn right.
• Lái xe tiếp một đoạn rồi rẽ phải. = Drive a bit more, then turn right.

So in the sentence, it works whether Lan is walking, driving, or just trying to follow directions.

Grammatically, Vietnamese phrases can sometimes be ambiguous, but in real context this sentence is normally understood as:

• Lan opens the map on her phone
• or Lan opens the map app / map display on the phone

That is because bản đồ trên điện thoại is a very natural modern expression for a digital map on a phone.

If you wanted to say a paper map physically placed on top of the phone, you would usually make the wording more explicit to avoid confusion.

This is standard punctuation for introducing direct speech.

• Lan mở bản đồ trên điện thoại và hỏi: introduces what she says
• then the exact words follow: Tôi nên đi thẳng hay rẽ phải?

In English, this works similarly:

• Lan opened the map on her phone and asked: Should I go straight or turn right?

Vietnamese writing often uses the colon plus quotation marks to present direct speech clearly.