Ma nincs nagy késés, ezért időben érkezünk a tanfolyamra.

In Hungarian, the verb van (to be / there is) has a special negative form in the present tense:

• van = there is
• nincs = there is not

So:

• nincs nagy késés = there is no big delay

You do not normally say nem van here.
This is one of the first special forms learners meet in Hungarian.

Ma means today. It is a time adverb, so it can easily come at the beginning of the sentence.

• Ma nincs nagy késés. = Today there is no big delay.

Putting ma first is very natural, because Hungarian often starts with the time expression when setting the scene.

Because Hungarian often leaves out the article when speaking in a general or indefinite way.

• nagy késés = a big delay / major delay
• nincs nagy késés = there isn’t a big delay / there isn’t any major delay

If you used an article, it would sound more like a specific, already-known delay. Here the idea is general: there is no significant delay.

Yes. Literally:

• nagy = big, large
• késés = delay, lateness

So nagy késés is literally big delay, but in natural English we would usually say a long delay, a serious delay, or a major delay, depending on context.

Hungarian often uses nagy where English prefers a less literal adjective.

Késés is a noun meaning delay or lateness.

It comes from the idea of being late:

• késik = to be late
• késés = lateness / delay

So:

• A busz késik. = The bus is late.
• Késés van. = There is a delay.

In your sentence, nincs nagy késés means there is no serious delay holding things up.

Ezért means therefore, so, or for this reason.

In this sentence:

• Ma nincs nagy késés, ezért időben érkezünk a tanfolyamra.
• Today there is no major delay, so we arrive on time to the course.

This is different from mert, which means because.

Compare:

• Késünk, mert nagy a forgalom. = We are late because the traffic is heavy.
• Nincs nagy késés, ezért időben érkezünk. = There is no big delay, therefore we arrive on time.

So:

• mert introduces the cause
• ezért introduces the result

Időben means on time or in time.

It comes from:

• idő = time
• -ban / -ben = in

So literally it is something like in time.

In real usage, időben is a very common adverb meaning:

• on time
• in time
• not late

Examples:

• Időben jöttél. = You came on time.
• Még időben szólt. = He/She warned us in time.

In your sentence, időben érkezünk means we arrive on time.

Hungarian often uses the present tense to talk about the future when the context already makes the time clear.

So:

• érkezünk literally = we arrive
• but in context it can mean we will arrive

Because the sentence is about what will happen today as a result of there being no delay, English may naturally translate it with a future idea:

• so we’ll arrive on time

This is very normal in Hungarian. A present form can refer to the future if the situation is clear.

The ending -ünk marks we.

The verb is:

• érkezik = he/she arrives

When conjugated for we, it becomes:

• érkezünk = we arrive

So you do not need a separate word for we, because the verb ending already tells you the subject.

That is why Hungarian often leaves out subject pronouns unless they are being emphasized.

Because -ra / -re often marks direction toward an event, activity, or occasion.

• tanfolyam = course
• tanfolyamra = to the course

Here the idea is arriving to attend the course, not physically going inside a container-like place.

This is similar to other event words:

• órára megyek = I’m going to class
• találkozóra megyünk = we’re going to a meeting
• koncertre érkeztek = they arrived for the concert

If you used -ba/-be, that would stress going into a physical place.
With tanfolyam, -ra is the natural choice when talking about attending the course.

The article a means the.

So:

• a tanfolyamra = to the course

The article is used because this is a specific course that both speaker and listener understand from context.

Hungarian uses definite articles quite a lot, but not always in exactly the same places as English. Here it matches English well: the course.

No, Hungarian word order is flexible, but changing it changes emphasis.

The given sentence:

• Ma nincs nagy késés, ezért időben érkezünk a tanfolyamra.

is a very natural neutral version.

Why it works well:

• Ma sets the time
• nincs nagy késés gives the situation
• ezért introduces the result
• időben is placed before the verb, which gives it strong focus: on time
• a tanfolyamra comes at the end as the destination

You could rearrange parts, but the emphasis would shift. For example:

• Ma ezért érkezünk időben a tanfolyamra sounds more marked
• A tanfolyamra időben érkezünk emphasizes the destination or the punctual arrival in a different way

So the original order is not the only possible one, but it is a very natural, learner-friendly model.

In Hungarian, the element right before the verb is often the most important or most focused piece of information.

So:

• időben érkezünk highlights on time

The sentence is effectively stressing the result:

• there is no big delay
• therefore we arrive on time

This pre-verbal position is very important in Hungarian word order, and learners will see it again and again.

More or less, yes:

• Ma = today
• nincs = there is not
• nagy késés = big delay
• ezért = therefore / so
• időben = on time / in time
• érkezünk = we arrive
• a tanfolyamra = to the course

A very literal version would be:

• Today there is no big delay, therefore we arrive on time to the course.

A more natural English translation would usually be:

• There isn’t much delay today, so we’ll get to the course on time.
• or There’s no major delay today, so we’ll arrive at the course on time.

So the Hungarian structure is quite transparent, even if natural English wording may change a little.