过去进行时的结构及句型变化
过去进行时由"was / were + 现在分词"构成。如:
I was doing my lessons then. 那时,我在做功课。
We were cleaning the house. 我们在打扫房子。
过去将来时态的肯定句、否定句和疑问句形式:
肯定句例句:I was walking down the street when a UFO landed.
否定句例句:I wasn’t walking down the street when a UFO landed.
一般疑问句例句:Were you walking down the street when a UFO landed?
特殊疑问句例句:What were you doing when a UFO landed?