by the time到……時候 at the time那時候
at times有時、間或 behind the times過時、陳舊
from time to time不時、有時 have a good/ great time玩得愉快
in time及時 once upon a time從前、以前 on time準時
take one‘s time慢慢來、不著急 time and time again一再
有時，at the time的後面可接“of...”短語。這時，它表示“在(某事態)發生的時候”或“在……的時代”。例如：
Were you in San Francisco at the time of the big earth quake in 1989﹖
1989年舊金山發生地震時，你在那裡嗎？
It happened at the time of King Alfred. 事情發生在阿爾弗雷德國王時期。
at that time 則通常指前文明確提到的某個時期、時候。通常其後不帶“of...”短語。例如：
In the 17th century much corn was grown in Tibet and Sichuan.At that time
(=At the 17th century) the land along the Changjiang River was becoming very crowded.
at one time=during a period of time in the past意為“過去有一段時期”，“曾經”。例如：
They used to be good friends at one time. 他們曾經是好朋友。
at a time則意為“一次”，表示一個時間單位。它常與表示數量的詞語連用，表示頻率。例如：
Don’t speak all at once.One at a time， please. 不要同時一起說。一次只一個人說。
Take the medicine three times a day and three pieces at a time. 這些藥每天服三次，每次服三粒。
by the time到……時候 at the time那時候
at times有時、間或 behind the times過時、陳舊
from time to time不時、有時 have a good/ great time玩得愉快
in time及時 once upon a time從前、以前 on time準時
take one‘s time慢慢來、不著急 time and time again一再
有時，at the time的後面可接“of...”短語。這時，它表示“在(某事態)發生的時候”或“在……的時代”。例如：
Were you in San Francisco at the time of the big earth quake in 1989﹖
1989年舊金山發生地震時，你在那裡嗎？
It happened at the time of King Alfred. 事情發生在阿爾弗雷德國王時期。
at that time 則通常指前文明確提到的某個時期、時候。通常其後不帶“of...”短語。例如：
In the 17th century much corn was grown in Tibet and Sichuan.At that time
(=At the 17th century) the land along the Changjiang River was becoming very crowded.
at one time=during a period of time in the past意為“過去有一段時期”，“曾經”。例如：
They used to be good friends at one time. 他們曾經是好朋友。
at a time則意為“一次”，表示一個時間單位。它常與表示數量的詞語連用，表示頻率。例如：
Don’t speak all at once.One at a time， please. 不要同時一起說。一次只一個人說。
Take the medicine three times a day and three pieces at a time. 這些藥每天服三次，每次服三粒。