While I came into the classcroom today,

While I was eating dinner last night,

While I was cleaning my teeth last night,

While I was doing my homework last night,

When I left the house this morning,

While I came into the classroom today, I was singing a song. While I was eating dinner last night, I broke a plate. While I was cleaning my teeth last night, I felt toothache. While I was doing my homework last night, I fell asleep.

When I left the house this morning, I was thinking about my plans for this evening.