Learn Hardcore Dutch: Omdat het koud is, wachten we binnen tot we kunnen instappen. - Because it is cold, we wait inside until we can board.

In Dutch, when you introduce a subordinate clause with a conjunction like omdat (“because”), the finite verb shifts to the very end. In a main clause you’d say het is koud, but after omdat you must say omdat het koud is.

Why do we invert in the main clause to wachten we binnen instead of we wachten binnen?

Because your sentence begins with a subordinate clause (Omdat het koud is), the following main clause still counts as “normal” word order, but the first element is now the subordinate clause. Dutch requires that the verb of the main clause immediately follows that first element, so you get wachten we binnen (verb – subject – rest). If you started with We wachten binnen, you would not need this inversion.

Why is there a comma after omdat het koud is?

Whenever a subordinate clause comes before the main clause, Dutch punctuation normally calls for a comma to mark the boundary. That comma helps readers see where the “because‑clause” ends and the main clause begins.

What exactly does binnen mean here, and could I use something else?

Here binnen is an adverb meaning “inside.” It tells us where you wait. You could also say in huis (“in the house”), but binnen is shorter and very common for simply “inside.” You wouldn’t use binnenin in this context.

What is the function of tot in tot we kunnen instappen, and can I use totdat instead?

Tot here is a conjunction meaning “until.” It introduces another subordinate clause: we kunnen instappen. You could also use totdat interchangeably: totdat we kunnen instappen. In speech most people shorten it to tot; in formal writing totdat is equally correct.

Why does kunnen instappen appear at the end of that clause, and what happens to the separable verb instappen?

Since tot also introduces a subordinate clause, all verb elements go to the end. You have a modal verb kunnen + the separable verb instappen. In subordinate clauses you keep them together as a block at the very end: …tot we kunnen instappen. In a main clause you’d say we stappen in or we kunnen instappen, splitting instappen into stappen … in.

How would the sentence change if I started with the main clause first?

If you put We wachten binnen first, you don’t invert, and the subordinate clause comes after, so you get:
We wachten binnen totdat we kunnen instappen omdat het koud is.
Or more naturally:
We wachten binnen omdat het koud is totdat we kunnen instappen.
In this order, each subordinate clause still sends its verb to the end of its own clause.