I was looking for the meaning of "cast" and I came across these examples from the Cambridge Dictionary:
to send light or shadow (= an area of darkness) in a particular direction:
• The moon cast a white light into the room.
• The tree cast a shadow over/on his face.
• (figurative)Her arrival cast a shadow over/on the party (= made it less pleasant). https://www.google.com/amp/s/dictionary.cambridge.org/amp/english/cast
Why for the 3 cases above we don't add an "s" to the verb after the singular nouns?