Đang chuẩn bị liên kết để tải về tài liệu:
Những từ cần phân biệt và cách dùng

Tài liệu tham khảo cho các bạn học tiếng anh tốt | We also use 'could' to talk about possible actions now and in the future - here the function is possibility (not ability) - and this is what tends to cause the confusion around these words. For example, if you are expecting some friends to visit, but they have been delayed, you might say 'they could arrive at any time now', or if you're trying to make progress with your work you might ask 'Could we talk to the boss again? For this function of possibility, we need to watch out for the past form, as this doesn't work in exactly the same way. If we want to express past possibility, we need to use could + have and the past participle (have done, have been etc). Let's imagine you've received a letter or card from a mystery admirer, and you're trying to work out who sent it to you. As the sending happened in the past, we are speculating about a past possibility. 'John could have sent it' but perhaps 'James could have written it'.we are not sure who, but think there are some possibilities.