Gosti dolaze jedan po jedan.

Because gosti is the nominative plural form, and the nominative is used for the subject of the sentence.

Here, gosti are the ones doing the action of arriving, so nominative is required.

• gost = guest
• gosti = guests

By contrast, goste is usually the accusative plural, which you would use when guests are the object of a verb, for example:

• Vidim goste. = I see the guests.

So in Gosti dolaze..., gosti is correct because the guests are the subject.

Because the subject gosti is plural, so the verb must also be plural.

• dolazi = he/she/it comes or is coming
• dolaze = they come or are coming

Since gosti means guests (more than one), Croatian uses:

• Gosti dolaze. = The guests are coming / The guests come.

So this is just normal subject-verb agreement.

The dictionary form is dolaziti.

That verb is imperfective, which is the normal choice here because the sentence describes an action in progress, repeated, or unfolding.

So:

• dolaziti → dolaze

A learner may compare it with doći (to come, perfective), but dolaziti fits much better when you mean that people are arriving one after another, not just that the action is viewed as a single completed event.

It is a very common Croatian expression meaning one by one.

The pattern is:

• jedan po jedan
• literally something like one, one at a time

You should think of it as a fixed distributive expression, not as a word-for-word structure that matches English perfectly.

It tells you that the guests are not arriving all at once, but individually, in sequence.

Because the phrase jedan po jedan focuses on each individual member of the group.

So even though gosti is plural, the expression treats them as:

• one guest
• then another guest
• then another guest

In other words, the sentence is about a plural group, but the arrival happens person by person.

That is why the distributive phrase uses the singular.

Yes, it usually matches the gender of the individual item/person being talked about.

For example:

• Gosti dolaze jedan po jedan.
  masculine: guest = gost

• Gošće dolaze jedna po jedna.
  feminine: guest (female) = gošća

• Djeca ulaze jedno po jedno.
  neuter singular idea behind djeca is dijete

So the pattern changes depending on what is arriving or happening one by one.

Here po has a distributive meaning.

In this sentence, it helps create the idea of:

• one at a time
• one by one

This is different from some other common meanings of po, such as location, movement, or per in other contexts.

So in jedan po jedan, po is part of the fixed pattern that expresses sequential distribution.

Yes. Jedan za drugim is also possible and often very close in meaning.

Compare:

• jedan po jedan = one by one
• jedan za drugim = one after another

In many situations, they are nearly interchangeable. But there is a small nuance:

• jedan po jedan emphasizes individual, separate arrival
• jedan za drugim emphasizes succession, the idea that one follows another

So both are good, but jedan po jedan is especially natural for one at a time.

It can mean either, depending on context.

Croatian present tense often covers both:

• are coming
• come

So Gosti dolaze jedan po jedan could mean:

• the guests are arriving one by one right now
• the guests come one by one as a general description of how they arrive

Usually the wider context tells you which meaning is intended.

No, Croatian word order is fairly flexible, although the version here is the most neutral and natural:

• Gosti dolaze jedan po jedan.

You may also hear or see variations for emphasis, such as:

• Jedan po jedan, gosti dolaze.

That sounds more marked or stylistic. For a learner, the original order is the safest default.

Because Croatian does not have articles like English the or a/an.

So gosti can mean:

• guests
• the guests

The exact meaning depends on context.

That is normal in Croatian. You do not need to add anything to express the.

Yes, it sounds natural.

It is a normal way to describe a situation where guests are arriving individually rather than all together.

It is simple, idiomatic Croatian:

• Gosti = subject
• dolaze = present-tense verb
• jedan po jedan = natural distributive expression

So this is a very useful pattern to remember and reuse with other nouns and verbs.