Learn Hardcore Vietnamese: Ngày mai, tôi sẽ đến công ty bằng xe buýt. - Tomorrow, I will go to the company by bus.

Literal role: It signals that the action (đến công ty bằng xe buýt – go to the company by bus) happens in the future.
Not strictly necessary: Vietnamese verbs don’t change form for tense, and time is often shown by context or time words like ngày mai (tomorrow).

So you can also say:

Ngày mai, tôi đến công ty bằng xe buýt.

This is still understood as future because of ngày mai. Using sẽ just makes the future sense more explicit or a bit more “planned” or “certain,” but in everyday speech it’s very common to drop sẽ when there is already a clear time expression.

Why does the sentence start with Ngày mai? Can it go somewhere else?

Putting Ngày mai (tomorrow) at the beginning is a very natural way to set the time frame in Vietnamese, just like “Tomorrow, I will go…” in English.

You can move ngày mai, but not everywhere sounds equally natural:

Ngày mai, tôi sẽ đến công ty bằng xe buýt. ✅ (very natural)
Tôi ngày mai sẽ đến công ty bằng xe buýt. 😐 (understandable but a bit clunky in neutral speech)
Tôi sẽ đến công ty bằng xe buýt ngày mai. ✅ (also acceptable; sounds a bit more like you’re adding “tomorrow” as an afterthought)

Basic guideline:

Time words (hôm qua, hôm nay, ngày mai, sáng nay, tối mai, etc.) usually come at the beginning or the end of the clause, with the beginning position being more common in careful or neutral speech.

What’s the difference between đến and đi? Why not just say tôi sẽ đi công ty?

Đi = to go (movement away from the speaker in general).
Đến = to arrive / to come to (emphasizes reaching a destination).

With locations, you normally say:

đi đến + place = go to (and arrive at) a place.
Or you can often just say đến + place if the movement is clear.

So:

Tôi sẽ đến công ty. ✅ (I will come/arrive at the company.)
Tôi sẽ đi đến công ty. ✅ (I will go to the company.)

But:

Tôi sẽ đi công ty. ❌ sounds wrong/unnatural.
With đi, you usually need đến or a preposition-like word after it (e.g. đi đến trường, đi lên Hà Nội, đi vào thành phố).

Why đến công ty and not something like “to my office”? Does công ty mean “my company”?

Công ty literally means company. In everyday speech, when people talk about going to work, several expressions are possible:

đến công ty – go/come to the company (often understood as my company by context)
đi làm – go to work (focusing on the activity, not the place)
đến chỗ làm – come to the workplace
đến văn phòng – come to the office (more specifically office rather than the whole company)

Your sentence:

Ngày mai, tôi sẽ đến công ty bằng xe buýt.
is naturally understood as “Tomorrow I will go to (my) company/office by bus,” even though của tôi (my) is not said. Vietnamese usually omits possessive pronouns when the owner is obvious from context.

What does bằng mean in bằng xe buýt?

Bằng here is a preposition meaning “by / by means of / using.” It introduces the means or instrument used to perform an action.

Common patterns:

bằng xe buýt – by bus
bằng xe máy – by motorbike
bằng ô tô / bằng xe hơi – by car
bằng tàu hỏa – by train
bằng tay – by hand

Position in the sentence:

It typically comes after the main verb phrase:
- tôi sẽ đến công ty bằng xe buýt – I will come to the company by bus.

Why is there no classifier before xe buýt? Should it be một chiếc xe buýt or something?

Vietnamese uses classifiers (like chiếc, con, cái) mainly when:

You’re counting: một chiếc xe buýt (one bus), hai chiếc xe buýt (two buses); or
You want to refer to one specific object in a particular way.

For means of transport in general, when you just say “go by car/bus/motorbike,” you don’t normally use a classifier:

đi bằng xe buýt – go by bus
đi bằng xe máy – go by motorbike
đi bằng xe đạp – go by bicycle

So bằng xe buýt is the natural, standard form here. Adding a classifier would sound unnatural in this context.

Is tôi always the right word for “I”? Could I use anh, em, or mình here instead?

Tôi is a neutral, polite pronoun for “I”, acceptable in most formal and neutral contexts, especially with strangers, colleagues, in writing, or in class.

However, Vietnamese pronouns depend heavily on age, relationship, and context. In real conversation, you might say:

Anh (I) – if you’re a man older than the listener.
Em (I) – if you’re younger than the listener.
Chị (I) – if you’re a woman older than the listener.
Mình (I) – more intimate/friendly, like “I (your friend/partner).”

So all of these could be used in the same sentence, but they change the social relationship implied. For learning purposes and general correctness, tôi is a safe, standard choice:

Ngày mai, tôi sẽ đến công ty bằng xe buýt. ✅

Do I have to say ngày mai, or can I just say mai?

Both are correct, but the nuance is slightly different:

ngày mai – literally “the day tomorrow”; slightly more complete/neutral.
mai – more casual/short; very common in speech.

You can say:

Mai, tôi sẽ đến công ty bằng xe buýt. ✅ (very natural in conversation)
Ngày mai, tôi sẽ đến công ty bằng xe buýt. ✅ (natural in both speech and writing)

In most everyday situations, mai is perfectly fine and common.

If I already have ngày mai, do I still need sẽ? What changes if I remove it?

You don’t need sẽ if ngày mai is there. Both of these are possible:

Ngày mai, tôi sẽ đến công ty bằng xe buýt.
Ngày mai, tôi đến công ty bằng xe buýt.

Differences:

Both are understood as future because of ngày mai.
Sentence 1 (with sẽ) sounds a bit more explicit and sometimes more “planned” or a bit more formal.
Sentence 2 (without sẽ) is very natural and common in everyday speech; Vietnamese relies heavily on time words/context instead of tense markers.

Is there any difference between saying đến công ty and đi làm?

Yes, a nuance difference:

đến công ty – focuses on the place (the company/office as a location).
đi làm – focuses on the activity (going to work, to do your job).

So:

Ngày mai, tôi sẽ đến công ty bằng xe buýt.
= Tomorrow I will go to the company (by bus).
Ngày mai, tôi sẽ đi làm bằng xe buýt.
= Tomorrow I will go to work (by bus).

In real life, đi làm is extremely common when talking about going to work. Both are correct; which one you use depends on whether you’re emphasizing the workplace as a location (công ty) or the act of working (làm).

How is the sentence broken down by syllables and tones?

The sentence has these words (each word is usually one syllable in Vietnamese):

Ngày – rising tone (dấu huyền? Actually ngày uses dấu huyền? No: it uses dấu huyền? It looks like “à” type: a with grave accent = huyền, ngày is low-falling; for learners, just memorize the tone shape)
mai – level tone (no mark)
tôi – falling-rising tone (dấu sắc? Actually “tôi” has “ôi” with a tone mark: tôi is falling tone – dấu nặng? In any case, learners usually learn it as a specific pitch pattern)
sẽ – dipping tone (dấu nặng with short, low, glottal stop)
đến – high rising tone (dấu sắc)
công – level tone (no mark)
ty – level tone (no mark)
bằng – low-falling tone (dấu huyền)
xe – level tone (no mark)
buýt – high rising tone (dấu sắc on y: buýt)

In practice, for speaking, it’s more useful to:

Learn each word with its tone as a package (ngày, mai, tôi, sẽ, etc.).
Pay attention to the written tone marks and practice slowly word by word, then connect them in a natural rhythm.

Where would I put additional time words like “in the morning”? For example, “Tomorrow morning I will go to the company by bus.”

You can combine time expressions, and their typical order is from larger to smaller (day → part of day → clock time). Examples:

Ngày mai buổi sáng, tôi sẽ đến công ty bằng xe buýt.
Sáng mai, tôi sẽ đến công ty bằng xe buýt. (more natural/compact)

Other possible positions:

Ngày mai buổi sáng tôi sẽ đến công ty bằng xe buýt.
Ngày mai, tôi sẽ đến công ty bằng xe buýt vào buổi sáng. (less common; sounds like you’re adding “in the morning” as extra info at the end)

General pattern:

[Time: day] + [Time: part of day]
Subject (tôi)
Future marker (sẽ, if used)
Verb + place (đến công ty)
Means (bằng xe buýt)
Extra time or manner info (optional).