Ons is al by die stasie.

Ons usually means we or us. Afrikaans uses the same form for both the subject and the object.

• Ons is al by die stasie. = We are already at the station.
• Hy sien ons. = He sees us.

In your sentence, ons is the subject, so it means we.

Afrikaans is very simple here: the verb is is used for all persons in the present tense of to be.

• Ek is = I am
• Jy is = you are
• Hy/Sy is = he/she is
• Ons is = we are
• Julle is = you all are
• Hulle is = they are

So ons is is completely normal. Unlike English, Afrikaans does not change the form to are.

Here, al means already.

So Ons is al by die stasie means that the group has already arrived at the station.

A useful thing to know is that al can have other meanings in other contexts, but in this sentence the meaning is clearly already.

Not in this sentence.

Although al can sometimes relate to the idea of all, here it means already, not all.

Compare:

• Ons is al by die stasie. = We are already at the station.
• Al die mense = All the people
• Alles = everything

So you should understand al from the context.

By is a preposition. It often means at, by, near, or sometimes with, depending on context.

In this sentence, by die stasie means at the station.

Some examples:

• Ek is by die huis. = I am at home.
• Sy sit by die venster. = She is sitting by the window.
• Hy bly by sy ouma. = He stays with his grandmother.

So by is a flexible word, and here at is the best translation.

Die is the Afrikaans definite article, meaning the.

One nice feature of Afrikaans is that die does not change for gender the way it does in some other languages. It is used very widely for the, whether the noun is singular or plural.

• die stasie = the station
• die man = the man
• die vrou = the woman
• die kinders = the children

So die stasie simply means the station.

Yes. Stasie is the Afrikaans word for station, and it is clearly related to the English word.

Its plural is:

• stasie = station
• stasies = stations

So if you wanted to say We are already at the stations, you would use die stasies, though that would be a less common situation.

This is the normal word order for a simple main clause in Afrikaans:

• Subject: Ons
• Finite verb: is
• then other information: al by die stasie

A very important rule in Afrikaans is that in a main clause, the finite verb usually comes second.

So:

• Ons is al by die stasie.

If you move another element to the front for emphasis, the verb still stays in second position:

• By die stasie is ons al.

That version is more marked or emphatic, but it still follows the same basic rule.

Yes. Reeds can also mean already.

So both are possible:

• Ons is al by die stasie.
• Ons is reeds by die stasie.

The difference is mostly in style:

• al is very common and natural in everyday speech
• reeds can sound a bit more formal, careful, or written

For casual spoken Afrikaans, al is extremely common.

It usually means at the station, but the exact physical meaning can depend on context.

It could mean:

• at the station building
• at the station area
• near the station, if that is how speakers are using it in context

If you specifically want to say inside the station, you would more likely say:

• in die stasie = in the station

So by die stasie is best understood as at the station unless the context says otherwise.

A rough pronunciation guide is:

Ons is al by die stasie
≈ ons iss ahl bay dee STAH-see

A few notes:

• ons sounds roughly like English onss
• is sounds like iss
• al is roughly ahl
• by sounds like bay
• die (the article) is pronounced dee
• stasie is roughly STAH-see

This is only an approximation, but it is close enough to help an English speaker get started.

Yes, it is completely natural.

It sounds like something someone would really say in everyday life, especially when telling someone that they have already arrived:

• Waar is julle? = Where are you all?
• Ons is al by die stasie. = We are already at the station.

So this is a very useful real-life sentence pattern.