tailieunhanh - Oxford practice grammar with answers part 31

Mark has spent three hours playing a computer game. He's been sitting there for three hours. It was two o'clock when Mark started the game. He's been playing since two o'clock. Three hours have passed since Mark and Sarah got up from the lunch table. They finished their lunch three hours ago. B For and since with the present perfect We often use for and since with the present perfect to talk about something continuing up to the present. FOR SINCE We use for to say how long something has continued. I've been waiting for forty minutes. We've known about it for two days. Melanie. | 121 For since ago and before FOR Mark has spent three hours playing a computer game. He s been sitting there for three hours. SINCE It was two o clock when Mark started the game. He s been playing since two o clock. AGO Three hours have passed since Mark and Sarah got up from the lunch table. They finished their lunch three hours ago. B For and since with the present perfect We often use for and since with the present perfect to talk about something continuing up to the present. FOR We use for to say how long something has continued. I ve been waiting for forty minutes. We ve known about it for two days. Melanie has been living here for a year now. SINCE We use since to say when something began I ve been waiting since ten past six. We ve known about it since Monday. Melanie has been living here since last year. We can also use for with other tenses. I m staying in England for a year. We swam for quite a long time. We can often leave out for but not from some negative sentences . We ve had this car for six months. I haven t seen Vicky for a day or two. C Ago with the past We can use the adverb ago to talk about a past time measured from the present. Six months ago means six months before now. I passed my driving test six months ago. NOT since six months Vicky wrote to the company weeks ago. David first met Melanie a long time ago. Have you seen Emma Yes just a few minutes ago. We put ago after the phrase of time NOT ago six months D Before with the past perfect We use before not ago with the past perfect . had done. I bought a car in August. I d passed my driving test three months before. in May three months before August Vicky finally received a reply to the letter she had written weeks before. 121 Exercises 1 For and since A-B Put in for or since. Daniel How long have you been learning English Ilona Well I studied it - for five years at school and I ve been having evening classes 1 .last summer. That s when I left school. Daniel And you re staying here 2 .three