when的用法四種句型：be doing sth…when；be about to do sth…when；hardly…when；had just done…when。
when的句型
1.be doing sth…when…
例：He was still smiling when the door opened and his wife came in.
他正笑著的時候門突然開了，他妻子走了進來。
2.be about to do sth…when…
例：We were about to start when it began to rain.
我們剛要出發，天就開始下雨了。
3.had not done sth…when…/hardly…when…
例：He had not fallen asleep when the telephone rang.
他剛要入睡電話就響了。
4.had just done…when…
例：I had just gone to bed after a very hard day when the phone rang. 在勞累了一天之後我剛剛就寢，電話鈴就響了。
when的用法四種句型：be doing sth…when；be about to do sth…when；hardly…when；had just done…when。
when的句型
1.be doing sth…when…
例：He was still smiling when the door opened and his wife came in.
他正笑著的時候門突然開了，他妻子走了進來。
2.be about to do sth…when…
例：We were about to start when it began to rain.
我們剛要出發，天就開始下雨了。
3.had not done sth…when…/hardly…when…
例：He had not fallen asleep when the telephone rang.
他剛要入睡電話就響了。
4.had just done…when…
例：I had just gone to bed after a very hard day when the phone rang. 在勞累了一天之後我剛剛就寢，電話鈴就響了。