Lịch hẹn là hôm nay.

Lịch hẹn usually means appointment, appointment schedule, or scheduled appointment.

It is made up of:

• lịch = schedule, calendar
• hẹn = appointment, arrangement to meet

So in this sentence, lịch hẹn refers to the appointment that has been set.

Depending on context, cuộc hẹn can also mean appointment, especially when you are thinking of the meeting itself rather than the booking or scheduled slot.

Là is the Vietnamese copula, similar to is / am / are in English.

In Lịch hẹn là hôm nay, it links:

• lịch hẹn = the appointment
• hôm nay = today

So the structure is basically:

• X là Y = X is Y

Vietnamese often does not use là before adjectives, for example:

• Trời nóng = It is hot

But when identifying or equating one thing with another, là is very common.

Vietnamese often puts the subject or topic first, then gives information about it.

So:

• Lịch hẹn = the appointment
• là hôm nay = is today

This is a very normal order in Vietnamese.
It is similar to saying in English:

• The appointment is today

If you changed the focus, you might use a different structure, but the original sentence is straightforward and natural.

Vietnamese usually does not need a preposition like on before common time expressions such as today, tomorrow, or yesterday.

So:

• hôm nay = today
• ngày mai = tomorrow
• hôm qua = yesterday

Examples:

• Tôi đi làm hôm nay = I am going to work today
• Lịch hẹn là hôm nay = The appointment is today

English needs on in some cases, but Vietnamese often does not.

Both can work, but they are not exactly the same.

• lịch hẹn often focuses on the scheduled appointment or booking
• cuộc hẹn often focuses on the actual meeting/appointment itself

So:

• Lịch hẹn là hôm nay can sound like you are talking about the scheduled date in a system or calendar
• Cuộc hẹn là hôm nay can sound more like the actual appointment event

If you are talking about something like a doctor’s appointment or a booking time, lịch hẹn is very natural.

You can say Lịch hẹn hôm nay, but it usually does not mean the same thing.

Most often, lịch hẹn hôm nay means:

• today’s appointment

That is a noun phrase, not a full sentence.

By contrast:

• Lịch hẹn là hôm nay = The appointment is today

So là helps make it a complete statement.

Vietnamese does not have articles like a, an, and the.

So lịch hẹn can mean:

• an appointment
• the appointment

The exact meaning depends on context.

If Vietnamese speakers want to make it more specific, they can add words like:

• lịch hẹn này = this appointment
• lịch hẹn đó = that appointment
• lịch hẹn của tôi = my appointment

Hôm nay means today.

Here:

• hôm is part of a day/time expression
• nay means this/now in this expression

Learners should treat hôm nay as a set phrase meaning today.

You will also see:

• hôm qua = yesterday
• hôm kia = the day before yesterday

By itself, hôm is not usually used the same way English uses day in everyday speech.

A rough pronunciation guide is:

• lịch: roughly like lik, with a heavy low tone
• hẹn: roughly like hen, also with a heavy low tone
• là: roughly lah, with a falling tone
• hôm: roughly hohm
• nay: roughly nai as in night without the final t

Tone-wise:

• lịch = nặng tone
• hẹn = nặng tone
• là = huyền tone
• hôm = level tone
• nay = level tone

The tones matter a lot, so it is best to listen to a native speaker or audio recording as well.

Sometimes, yes, but you usually need to change the sentence a little.

Natural alternatives include:

• Hôm nay có lịch hẹn = There is an appointment today
• Hôm nay là ngày hẹn = Today is the appointment day

Simply switching the words mechanically does not always produce the most natural Vietnamese.
So instead of just moving hôm nay, it is better to use a structure that Vietnamese speakers would actually say.

A common yes-no question would be:

• Lịch hẹn là hôm nay phải không? = The appointment is today, right?
• Lịch hẹn là hôm nay à? = Is the appointment today?

A negative version would be:

• Lịch hẹn không phải là hôm nay = The appointment is not today

Here, không phải là is the standard pattern for is not / are not in this kind of sentence.