“All that” / “all what” / “all which” in English

by Jakub Marian

Tip: See my list of the Most Common Mistakes in English. It will teach you how to avoid mis­takes with com­mas, pre­pos­i­tions, ir­reg­u­lar verbs, and much more.

English learners often use an incorrect pronoun after the word “all”. Long story short, what you most likely want to say is “all that …”, as in

correct All that glitters is not gold.
wrong All what glitters is not gold.
wrong All which glitters is not gold.

The confusion stems from the fact that “all” is followed by “what” in many other languages, e.g. alles was in German. If you feel the need to say “all what” in English, the best option is usually to leave out the pronoun altogether:

correct This is all you need to know.
wrong This is all what you need to know.

“All which” would not be wrong, but it sounds rather formal and outdated (it was somewhat widespread before the 19th century).

This article was based on my guide to the most common mistakes in English, which explains many similar topics. Why don’t you check it out?