One też czekają na autobus.

Polish has two common plural words for they:

• oni: for groups that include at least one male person
• one: for groups with no male people, for example a group of women, children, animals, or things

So one here tells you that the group is non-masculine-personal. In many real contexts, that means they (women).

No. One is often used for women, but not only for women.

It is also used for:

• children
• animals
• objects
• groups of people with no male members

So the form is grammatical, not purely biological. It depends on the grammatical type of the group.

Czekają is the 3rd person plural present tense of czekać.

So it means:

• they wait
• they are waiting

Polish present tense often covers both the simple present and the English present continuous. The context tells you which English translation sounds best.

In the present tense, Polish uses the same 3rd person plural verb form for both:

• oni czekają
• one czekają

So the difference between oni and one is shown by the pronoun, not by the present-tense verb ending.

This difference becomes more visible in other parts of grammar, especially in adjectives and in the past tense.

Też means also or too.

So One też czekają na autobus means that they are also waiting for the bus or they too are waiting for the bus.

It adds the idea that someone else is waiting too, and this group is included as well.

Yes, Polish word order is fairly flexible, and moving też can slightly change the emphasis.

For example:

• One też czekają na autobus = They too are waiting for the bus
• One czekają też na autobus = closer to They are also waiting for the bus; this can sound like the bus is another thing they are waiting for
• Też czekają na autobus = They are also waiting for the bus, with the subject left unspoken

The original sentence is natural, especially if you want to emphasize they too.

Because czekać normally goes with na when you are waiting for someone or something.

The pattern is:

• czekać na kogoś / na coś = to wait for someone / something

So:

• czekać na autobus = to wait for the bus

This is just the standard construction Polish uses with this verb.

After czekać na, the noun usually goes into the accusative case.

But autobus is a masculine inanimate singular noun, and for that noun type, the accusative singular looks the same as the nominative singular.

So:

• nominative: autobus
• accusative: autobus

Even though the form looks unchanged, it is still functioning as accusative in the sentence.

Yes. Polish often drops subject pronouns because the verb already shows the person and number.

So Też czekają na autobus is possible and natural in context.

Including one usually adds emphasis or contrast, for example:

• We are waiting for the bus. They are too.
• My czekamy na autobus. One też czekają na autobus.

So the pronoun is not always necessary, but it can be useful.

No, not completely. Polish word order is more flexible than English word order.

The basic sentence:

• One też czekają na autobus

is natural and clear, but you can rearrange parts for emphasis, for example:

• Na autobus one też czekają
• Też one czekają na autobus
  This is possible, but less neutral and more marked.

English relies heavily on word order for grammar. Polish relies more on endings and uses word order more for focus, contrast, and style.