Also ‑st.
Forming the second person singular of verbs.
Old English ‑est, ‑ast, ‑st.
This ending, like ‑eth for the third person singular (see ‑eth2) is archaic. Examples include canst, comest, goest, knowest, sayest.
Copyright © Michael Quinion 2008–. All rights reserved. Your comments are very welcome.