English Grammar - Using the present perfect - 'have done'

Hello, I'm Oli. I'm a teacher from Oxford Online English. Today, we've got a free grammar lesson for you. Let's look at a sentence: "I've eaten five pineapples today." Lots of pineapples! But let's think more about this sentence and about the verb "I've eaten." Three questions: what is this verb, how do we make it and what does it mean? In this lesson we're going to think about these questions, especially the third question. So the first question this verb form 'I've eaten' is the present perfect. We make it by taking 'have' and a past participle. The past participle is the third form of the verb. So, for a verb like 'eat': eat, ate, eaten - 'eaten' is the past participle. Or, another one: do did done - 'done' is the past participle. So the third question is the most important: what does this mean? In this lesson I'm going to show you four easy ways to use this present perfect form. The first way is to talk about a time period which hasn't finished yet. Let's look our example sentence: "I've eaten five pineapples today." So think: is today finished? Well, no, of course not. If today was finished it would be yesterday. So when we use unfinished time periods we often use the present perfect. Let's look at some more examples. "I've spoken to her several times recently." So, recently is an unfinished time period, we use the present perfect. 'I've spoken'. "We've finished all our work for this week." 'This week' is unfinished so again we use the present perfect. "She's never been to Italy." 'Never' means in her life, and her life is unfinished, so we use the present perfect. So, let's look at a comparison. We said: "I've spoken to her several times recently." Let's compare that with another sentence: "I spoke to her a long time ago." So in this case 'a long time ago' is a finished time period, we don't use the present perfect, we use the past simple: 'I spoke.' Ok, let's look at point number two. We use the present perfect when something started in the past and is still happening now or is still true now. This is one of the most common ways to use the present perfect. Let's look at some examples. Number one: "I've lived here since I was born." That means I still live here now. "He's known her for thirty years," so they still know each other now. These are things which started in the past and are still happening now. Let's compare: we said, "He's known her for thirty years." What if we say: "He knew her when they were at university." How are those sentences different? Well, we said "He's known her for thirty years" means they still know each other now. "He knew her when they were at university," when we use the past simple like that we mean they don't know each other any more. So you can see the present perfect is often very different from the past simple tense. We use the past simple to describe finished actions or times, but we use the present perfect to describe things which are still important now. That takes us to number three: we use the present perfect when something happened in the past and the results are still important now. This is similar to number two, but not exactly the same, so let's look at some examples: "I've lost my book." Think: what does this sentence tell us about now? Why is this important now? Well, it's important because this means I don't have my book now. Let's look at another example: "He's eaten too much." Again, this means the result is important now, So that means probably he doesn't feel good, he's eaten too much and his stomach feels bad now. Again, let's compare to the past simple. If I say: "I lost my book," compared to "I've lost my book." Can you tell the difference? Well, "I've lost my book" we said means I don't have it now. "I lost my book" means maybe I found my book again, maybe I didn't. When I use the past simple here what I mean is it's not important now. I lost my book, we don't know what happened after that, we don't care. "I've lost my book," with the present perfect, that means this is important now. Ok, number four: we use the present perfect with 'just', 'yet' and 'already'. Again, this is similar to point number one but it's a useful point to remember. If you want to use these words in a sentence, you will often need to use the present perfect. So for example: "Have you sent it to him yet?" means I wanted you to do it before now. Or: "I've already finished everything" So it took less time than I expected. Or: "They've just arrived." So, they arrived a very short time ago. The present perfect is a complicated verb form to use, but if you understand the points in this lesson then you already have a good start. If you want more practice, come to our website: www.oxfordonlineenglish.com. You can find a text and exercises which go with this lesson, which can help you to practice the things we've talked about today. That's all for today, thank you very much for watching, I'll see you next time. Bye bye!