از when و while موقعي استفاده ميشه كه مي خواييم در مورد دو تا كار كه همزمان رخ ميدن صحبت كنيم:
I was sleeping when the teacher finished the lesson.
He was snoring while she was watching a movie.
فرق اين دو تا:
WHILE: درحاليكه، در طول مدتي كه
معمولا وقتي از اين كلمه استفاده مي كنيم، زمان انجام هر دو تا كار طولانيه
WHEN: (وقتی که، زمانی که، (گاهی اوقات: بعد از اینکه
معمولا وقتي از اين كلمه استفاده مي كنيم، زمان يكي از اون كارها طولاني و ديگري كوتاهه / يا اينكه زمان هر دو تا كار كوتاهه/ يا اينكه در مورد دوره اي از زندگي مون داريم صحبت مي كنيم ( وقتي بچه بودم, وقتي ازدواج كردم ، وقتي ليسانسم را گرفتم، وقتي ٢٠ سالم بود ، ...)، گاهی هم زمان انجام یه کار بعد از انجام کار دیگه است (یعنی دو تا کار دقیقاً همزمان نیستند)، که در اینصورت when به معنای "بعد از اینکه" است.
مثال:
1. The dog was barking. She was talking to her mother on the phone.
talking to her mother = long action
dog
barking = long or short (Did the dog bark for a long time? Did it bark for a short time?
اينجا نمي دونيم دو تا كار طولاني بودند يا نه، پس از هر دو كلمه ميشه استفاده كرد
The dog was barking when she was talking to her mother on the phone.
The dog was barking while she was talking to her mother on the phone.
2. She was doing the dishes. The telephone rang.
doing dishes = long action
phone
rang = short action.
اينجا يه كار طولاني يه كار ديگه كوتاه بوده پس
She was doing the dishes when the telephone rang.
3. The alarm bell rang. He was sleeping.
He was sleeping = long action
alarm bell rang = long or short action (Did it ring for a short time? Did it ring for a long time?)
باز اينجا نمي دونيم كه هر دو كار طولاني بودند يا نه.، پس ميشه از هر دوتا كلمه استفاده كرد
The alarm bell rang while she was sleeping.
The alarm bell rang when she was sleeping.
4. It was raining. I was watching a movie.
It was raining = long action.
I was watching a movie = long action
هر دو تا فعل طولاني بودند، پس
It was raining while I was watching a movie.
5. I saw lightning. I heard thunder.
saw lightning = short action
heard thunder = short action
هر دو تا كار كوتاه بودند ، پس
I saw lightning when I heard thunder.