Learn Dutch: Er zit een gaatje in de kurk. - There is a small hole in the cork.

This is an example of an irregular diminutive with a vowel shift. Some nouns with a short vowel in their base form lengthen that vowel when they become diminutives. The short 'a' in gat becomes a long 'aa' in gaatje.

Is this vowel shift related to how the plural of gat is formed?

Exactly! Just like the short 'a' in gat becomes a long sound in the plural gaten, it also lengthens in the diminutive gaatje. You will see this same short-to-long pattern in a few other common words, such as glas becoming glaasje or pad becoming paadje.

Why does the sentence use zit instead of is for 'there is'?

Dutch frequently uses posture verbs like zitten, staan, and liggen to describe where things are located, rather than just using zijn (to be). Because a hole is located inside or within the structure of the cork, zitten (to sit) is the natural choice to express this physical containment.

I have seen het kurk before. Why is it de kurk here?