1.Cơ sở phân biệt :
“Until” và “before” đều là liên từ , vì vậy dựa thuần tuý vào cấu trúc khó phân biệt được mà phải dựa vào các yếu tố khác .
- Động từ trong mệnh đề chính mang ý nghĩa kéo dài hay không kéo dài .
I waited until he returned.
I shaved before I went to the party.
- Động từ trong mệnh đề chính ở dạng khẳng định hay phủ định .
(1)The children will come back before it is dark.
(2)The children won't come back until/before it is dark.
- Sự việc trong mệnh đề phụ hiện thực hay không hiện thực .
Let's wait until the rain stops.
pig will fly before he'll become a mathematician.
- Dựa vào ý nghĩa của toàn câu .
(1)We discussed the problem until/before he came back.(Chúng tôi thảo luận đến lúc anh ấy về)
chúng tôi mới thảo luận )
2.Thực tế ngôn ngữ :
-Dùng được cả hai (until hoặc before )
(1)The noise of the street didn't stop until/before it was midnight. (2)The children won't come back until/before it is dark.
(3)I didn't leave the lovely boy until/before his mother came home. (1)He lived with his parents until/before he graduated from school. (2)I will wait until/before he comes to my help.
(3)I shall stay heer until/before you come back.
-Chỉ dùng “before” :
(1)He fell asleep before I could take off his clothes. (2)We arrived there before it atarted to rain.
(3)The holiday came to the end befor I knew it.
(1)It was quite some time before he found the elephant at all. (2)We had walked a long way before we found some water. (3)We had sailed for two days before we saw the land. (1)We can leave early in the morning before it gets too hot. (2)I must write it down before I forget it.
(3)We do want to buy something now before prices go up. (1)I would give up my job before I'd agree to be dismissed. (2)He will die of hunger before he will steal.
(1)It was not long before the whole country rose up.
(2)It will probably not be long before they understand each other. (1)I hope to finish the work before he arrives.
(2)I had not been there long before his arrival.
-Chỉ dùng “until”
(1)It was not until he told me that I knew it.
(2)It was not until he finished his homework that he went home. Động từ vị ngữ ở số nhiều hay số ít
Danh từ chỉ một tập hợp làm chủ ngữ : Nếu ý chỉ tổng thể thì động từ vị ngữ ở số ít . Nếu ý chỉ các thành viên tạo thành tập hợp đó thì động từ vị ngữ ở số nhiều . (adsbygoogle = window.adsbygoogle || []).push({});
So sánh các ví dụ sau:
His family are waiting for him.
But the man's family was small-only himself and his wife. One third of the population here are workers.
The population of the earth is increasing every year. The team is well organized.
The team are all tough players. All the class were jumping with joy. The class is made up of 54 students. The young couple is happy.
The young couple are quarrelling with each other. The village is at the foot of the mountain.
All the village are out to greet him.