1. The Irish are celebratingcelebrate Saint Patrick's Day on March 17.

2. I  am not knowingdon't know why he  calledwas calling you yesterday.

3. I  am not thinkingdon't think you should  be payingpay attention to what he says.

4. My sister  listenedwas listening to a CD when the bell  rangwas ringing. She immediately  stoppedwas stopping the CD player to see who was there.