tell a teacher, tell friends, beat them up.
A non-count noun is one the cannot be made plural.
The non-count noun in this sentence is rain.
To give an introduction to the play, lay the foundation of the story out to the audience.
Jealousy runs the characters' lives in Othello from the beginning of the play, when Roderigo is envi- ous of Othello because he wishes to be with Desdemona, and to the end of the play, when Othello is furious with envy because he believes Cassio and Desdemona have been engaging in an affair.