Learn Dutch: 'Het zij zo' is een bekende spreuk. - 'So be it' is a famous saying.

Zij is the present subjunctive form of the verb zijn (to be). The subjunctive is a verb form historically used to express a wish, command, or hypothetical situation. In modern Dutch, the present subjunctive is almost extinct and only survives in fixed, formulaic expressions like Het zij zo (So be it).

In what situations do Dutch speakers actually use Het zij zo?

You use it to express resignation or acceptance of a situation that you cannot change, much like 'It is what it is' in English. If you miss your train and have to wait an hour, you might shrug and say: Nou ja, het zij zo.

Are there other common expressions that use zij as a subjunctive?

Yes, you will spot it in a few other fossilized phrases. The most common one is God zij dank (Thank God, literally 'To God be thanks'). As a B2 learner, you do not need to learn how to conjugate verbs into the subjunctive; you just need to recognize these set expressions when you encounter them.

What is the difference between a spreuk and a spreekwoord?

They are similar but have different nuances. A spreekwoord is specifically a traditional proverb that states a general truth. A spreuk is a broader term for a saying, motto, slogan, or even a magic spell. Het zij zo fits perfectly as a spreuk because it acts as a short motto of resignation rather than a universal truth.