Đi bộ mỗi sáng là thói quen tốt.

Yes, đi by itself usually means to go. But đi bộ is a fixed expression meaning to walk or to go on foot.

• đi = go
• bộ = on foot

So together, đi bộ specifically means moving by walking.

Examples:

• Tôi đi bộ đến trường. = I walk to school.
• Tôi thích đi bộ. = I like walking.

In Vietnamese, a verb phrase can often act as the subject of a sentence without any extra word. So đi bộ mỗi sáng functions like walking every morning in English.

Structure:

• Đi bộ mỗi sáng = walking every morning
• là = is
• thói quen tốt = a good habit

So the whole sentence is built like:

[Walking every morning] [is] [a good habit].

Vietnamese does not need a special ending like -ing to turn the action into a subject.

Mỗi sáng means every morning.

• mỗi = every / each
• sáng = morning

So:

• mỗi ngày = every day
• mỗi tuần = every week
• mỗi sáng = every morning

In this sentence, mỗi sáng tells you when the walking happens.

Vietnamese often does not need a preposition where English does.

In English, we say:

• in the morning
• every morning

In Vietnamese, time expressions can often appear directly:

• sáng nay = this morning
• mỗi sáng = every morning
• ngày mai = tomorrow

So đi bộ mỗi sáng is perfectly natural without adding a word like in.

Là is the linking word, similar to is / am / are in sentences that identify or classify something.

Here it connects:

• đi bộ mỗi sáng → the subject
• thói quen tốt → what it is

So:

• A là B = A is B

In this sentence:

• Đi bộ mỗi sáng là thói quen tốt.
• Walking every morning is a good habit.

A useful point: Vietnamese sometimes omits là with adjectives, but when one noun phrase is being identified as another noun phrase, là is very common and usually needed.

Because in Vietnamese, adjectives usually come after the noun.

• thói quen = habit
• tốt = good

So:

• thói quen tốt = good habit
• người tốt = good person
• sách hay = interesting book

This is the opposite of normal English word order.

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

So thói quen tốt can mean:

• a good habit
• the good habit
• sometimes just good habit depending on context

Here, English naturally translates it as a good habit, but Vietnamese does not need a separate word for a.

You could, but it is less natural in this sentence.

• mỗi sáng is already a complete and natural time expression.
• Adding vào is usually unnecessary here.

Most natural:

• Đi bộ mỗi sáng là thói quen tốt.

Possible but less smooth:

• Đi bộ vào mỗi sáng là thói quen tốt.

Vào is more common in some other time expressions, especially when being more explicit:

• vào buổi sáng = in the morning
• vào ngày mai = tomorrow / on tomorrow’s date in some contexts

Yes. Both are possible, but they are used a little differently.

• sáng = morning
• buổi sáng = the morning / morning time

So you may hear:

• mỗi sáng = every morning
• mỗi buổi sáng = every morning

Both are natural. Mỗi sáng is shorter and very common in everyday speech. Mỗi buổi sáng can sound slightly fuller or a bit more formal.

It is neutral and natural. It works well in:

• conversation
• school writing
• health advice
• general statements

It sounds like a standard factual sentence. It is not slangy, and it is not unusually formal.

No, that sounds ungrammatical or very unnatural.

You need là here because thói quen tốt is a noun phrase, and the sentence is saying that one thing is another thing.

Correct:

• Đi bộ mỗi sáng là thói quen tốt.

By contrast, Vietnamese can sometimes omit là before an adjective:

• Cô ấy đẹp. = She is beautiful.
• not Cô ấy là đẹp in normal usage

But with a noun phrase like thói quen tốt, là is the normal choice.

You would usually say:

• Đi bộ mỗi sáng thì tốt.
• Đi bộ mỗi sáng rất tốt.

That changes the second part from a noun phrase to an adjective.

Compare:

• là thói quen tốt = is a good habit
• tốt = is good

So the original sentence emphasizes that it is a good habit, not just that it is good.

A learner may want to watch these tones carefully:

• đi — level tone
• bộ — nặng tone, short and low with a glottal stop feel
• mỗi — hỏi tone
• sáng — sắc tone
• là — huyền tone
• thói — sắc tone
• quen — level tone
• tốt — sắc tone

A few especially important contrasts:

• mỗi and moi are not the same
• bộ needs the dot below
• là should not be pronounced like flat la

Tones matter a lot, so it is good to learn the whole sentence as one rhythm unit:

• Đi bộ mỗi sáng là thói quen tốt.