Directions: Fill in the blank with the correct preposition: Do you usually go…

Key point: Use "on" with days and with parts of days that are tied to a day (for example, "Saturday evenings").

• "in" — months, years, seasons, and long periods (e.g., in July, in 2020, in the summer).

• "at" — precise times and certain fixed expressions (e.g., at 3:00, at noon, at night).

• "on" — days and dates, and parts of a day tied to a day (e.g., on Monday, on Saturday evening).

• "within" — during or inside a period (e.g., within a week), not used to name specific days.

Therefore, the correct preposition for the sentence "Do you usually go out __________ Saturday evenings?" is "on" because "Saturday evenings" refers to a day and a part of that day.