De tochtstrip sluit de kier.

Dutch very often forms compound nouns by writing the parts together as a single word.

• tocht = draft / cold air current
• strip = strip

So tochtstrip literally means something like draft-strip, which in natural English is draft excluder, weather strip, or seal depending on context.

This is extremely common in Dutch. English sometimes uses spaces where Dutch prefers one word.

Sluit is the present tense form of the verb sluiten.

The infinitive is:

• sluiten = to close / to seal

In this sentence, the subject is de tochtstrip, which is third person singular, so Dutch uses:

• ik sluit = I close
• jij sluit = you close
• hij/zij/het sluit = he/she/it closes

So De tochtstrip sluit de kier uses sluit because it means the draft strip closes/seals the gap.

Because this is a normal Dutch main clause, and Dutch usually puts the finite verb in the second position.

So the structure is:

• De tochtstrip = subject
• sluit = finite verb
• de kier = object

This is the standard word order for a simple statement in Dutch, and it matches English quite closely here:

• The draft strip / seals / the gap

Kier means a narrow gap, crack, or small opening, especially one that lets air, light, or cold through.

It is more specific than a general word like opening. A kier is usually:

• small
• narrow
• often unwanted
• often between a door, window, or frame

So in this sentence, de kier is the little gap that the strip is sealing.

In Dutch, every noun has a grammatical gender category, and singular common-gender nouns take de, while neuter nouns take het.

Both of these nouns are de-words:

• de tochtstrip
• de kier

Unfortunately, this usually has to be learned with the noun. There is not always a reliable rule you can guess from.

One useful clue here is that many nouns ending in -strip are common gender and take de, but in general it is best to memorize the article together with the noun.

Here it is closer to to seal or to shut off than to simply to close.

In Dutch, sluiten can mean:

• to close a door
• to shut something
• to seal off an opening

So in De tochtstrip sluit de kier, the idea is that the strip closes up the gap so air cannot pass through it.

English might translate it more naturally as:

• The draft strip seals the gap rather than
• The draft strip closes the gap

Both are understandable, but seals sounds more natural in this context.

Yes. Tocht can have more than one meaning in Dutch.

Common meanings include:

• tocht = trip / journey / tour
• tocht = draft / cold airflow

In tochtstrip, it means draft, not journey.

This is just a case of one Dutch word having multiple meanings. The compound makes it clear which meaning is intended: a tochtstrip is something used against cold air coming through gaps.

Approximate pronunciation:

• tochtstrip: the first part has the Dutch ch sound, the harsh throat sound also heard in gracht or Scottish loch
• kier: roughly like keer in English spelling, but with a Dutch ie sound, which is like ee in see

Very roughly for an English speaker:

• tochtstrip ≈ tohkht-strip
• kier ≈ keer

The hardest part is the ch in tocht. It is not like English ch in chair.

Yes, that is possible, and it sounds quite natural too.

• sluit de kier = closes/seals the gap
• dicht de kier = seals up the gap

The verb dichten often means to seal, to stop up, or to close off an opening. In some contexts, it can sound even more specific than sluiten when talking about gaps, cracks, or leaks.

So the original sentence is correct, but dicht is another useful option to know.

Because sluiten already works on its own here.

Dutch has many verbs that can appear either:

• as a simple verb, or
• with a particle such as af, aan, op, etc.

For example, afsluiten often means to seal off, to shut off, or to close off completely.

So you may also see something like:

• De tochtstrip sluit de kier af

That would emphasize closing off the gap. But the simple sluit is also perfectly fine and natural in this sentence.