All instances of "you" and "your" are plural. However, Jesus is telling them what will happen to them as individuals if each person does not forgive others. (See: [[rc://en/ta/man/translate/figs-you]])
The abstract noun "trespasses" can be translated as a verb. Alternate translation: "when they trespass against you" (See: [[rc://en/ta/man/translate/figs-abstractnouns]])