Your friend has invited you to the disco next Saturday but you can't go.
( сочинение)

Будет в форме диалога.—Hello, Alex! I have free Saturday. We can go to the disco. I love it!—Oh, sorry. I can`t go. I`ll stay with my little sister all the day.—Why can`t your parents do this?—They go for a work all day.—Great! So, can I go to you? I`ll bye many pizza and chips!—But what about my sister?—We`ll sit with her! What problems? I have a free day, so I want to spend it with benefit (польза)! I would like to learn how to treat (обращаться) with little children!—Oh, it would be nice! OK, I wait you on Saturday in my house!—No problems! Goodbye!—Goodbye!