Why can't you come on Sue's birthday party on Tuesday?
I help at the zoo on Tuesdays. / On Tuesdays, I help at the zoo.
Why can't you come on Sue's birthday party on Monday?
I have piano lessons on Mondays. / On Mondays, I have piano lessons.
Why can't you come on Sue's birthday party on Saturday?
I go to the library on Saturdays? / On Saturdays, I go to the library.
Why can't you come on Sue's birthday party on Friday?
I have guitar lessons on Fridays. / On Fridays, I have guitar lessons.
Why can't you come to Sue's birthday party on Thursday?
I go to my grandmother's house on Thursdays.
Why can't you come on Sue's birthday party on Wednesday?
I practise hockey on Wednesdays. / On Wednesdays, I practise hockey.