The present perfect has a couple of uses, and if you understand the ways it is used, remember them, and practice, you're on your way to mastering this tense. First, however, you should know the structure. The present perfect uses "have" or "has" as an auxiliary verb and the past participle as a main verb. In other words, the present perfect of "she eats" is "she has eaten"; the present perfect of "they drove" is "they have driven," and for "I wrote," it's "I have written."
We use the present perfect to talk about something you have done already. However, you cannot say when you did it. In other words, you cannot use specific time. Otherwise, you'll have to use the past tense.
Here are some examples of sentences in the present perfect and the past tense. The ones with specific time are in the past tense, while the ones without specific time are in the present perfect.
1. I have already eaten. - present perfect
I ate 2 hours ago. - past tense
2. He has taken out the garbage. - present perfect
He took out the garbage when he got home. - past tense
3. She has done her homework. - present perfect
She did her homework before dinner. - past tense
Similarly, we use the present perfect to talk about our experiences without saying when we experienced them. Like the above examples, we have to use the past tense if we want to say exactly when we did them. Here are some examples.
1. They have been to China. - present perfect
They were in China in 2010. - past tense
2. She has gone bungee jumping twice. - present perfect
She went bungee jumping when she visited New Zealand and Peru. - past tense
3. He's kind of nuts. He has even swum with sharks before. - present perfect
He swam with sharks last summer. - past tense
We also use the present perfect to talk about action that started in the past and continues to the present. This is usually used with for (to indicate duration) or since (to indicate the beginning of the action). Here are some examples.
1. They have lived in Miami for 10 years now.
2. She has studied English since she was 10 years old.
3. I've worked at this job since 2009.
The sentences above all show action that started in the past and continues to the present. A quick note: this particular usage can have a similar meaning as the present perfect progressive.
Alright, folks. Practice makes perfect, so read and reread, then practice as much as you can. Look out for exercises on verb tenses at the small guide site in the future. Any questions? Feel free to leave a comment below, on the small guide site page on Facebook or tweet me a message @joeyu2nd on Twitter. Catch you again soon.