Nota:Lembran-se que o uso de present perfect para as pessoas que falam portugués pode parecer um pouco complexo no começo. Eu prometo que não é. Porém estou adicionando esta postagem para ser como um suplemento para eles que já estudarem bastante o tema, por isso escolhei botar tudo em inglês, para que esforcem mais. Se tiver dúvida pode perguntar até em português. Vale ler esta postagem em português primeiro PRESENT PERFECT vs. PRETÉRITO PERFEITO COMPOSTO.
Lembram-se também que além do uso de ênfase, temos o uso principal de fazer ou responder (afirmações) sobre
1) o tempo de hoje (o presente) para atras, o que descrevo assim "uma vez na sua vida"
e também
2) para um tempo definido até hoje (o presente), o que descrevo por uma quantidade de tempo.
O primeiro exemplo usa palavras de frequência e as mais comunas são ever, yet, already e never. Exemplo: Have you ever went to the bakery on first avenue?
No, I never have.
O segundo exemplo refere-se desde que algo aconteceu até agora mesmo. Palavras-chaves são for, since, in juntadas com uma quantidade de tempo.
Exemplo: Have you seen my cellphone? ( está implicado "since I lost it" e pode estar incluído).
No, I haven't seen it (since you lost it). Aqui não está dizendo que uma vez na sua vida porém desde aconteceu tal ação até o presente.
Sobre estes temas se trata este artigo em inglês. Enjoy!
Present perfect + a length of time
The Basics
1. What does present perfect meaning #1 mean?
When I use present perfect with a phrase that shows a length of time
like “for two hours,” “since 1911,” “since I came to America” or “twenty
minutes,” then it usually means that the action started in the past and has
continued until now.
Examples:
Norton has studied English for the past three semesters. (Norton started
studying three semesters ago and has continued until now.)
Ludwig has worked at McDonald’s since last March. (Ludwig started
working there last March and has continued until now.)
Fred and Ethyl have owned this building a long time. (Fred & Ethyl
bought the building in the past and have continued to own it until
now.)
Has Lulu worked at Costco since she graduated from high school? (I
want to know if Lulu started working when she graduated and
has continued until now.)
I haven’t seen Norton for three years. (This situation [not seeing Norton]
started in the past and has continued until now.)
Why have you been quiet for so long? (I want to know why you started to
be quiet in the past and have continued to be quiet until now.)
Joe hasn’t smoked ever since his doctor told him to stop. (Joe stopped
smoking when his doctor told him to and this situation has continued
until now.)
Melvin has smoked since he was seventeen. (He started this habit when
he was seventeen and has continued the habit until now.)
Part 2:
More That You Should Know about Present Perfect Meaning #1
1. When should I use present perfect meaning #1?--A simple rule
Present perfect meaning #1 and present perfect progressive mean the same thing; they both mean that the action started in the past and has continued until now. If we draw a picture of this meaning, it looks like this:
past time right now future time
l
l
l
l
The action started in the past, l
unit now. l
_______________________________l_______________________________ l l
l l
l l
l l
l_________________>l unit now.
has continued l
l
l
If present perfect meaning #1 and present perfect progressive mean the same thing, that raises the question, “How do I know when to use present perfect and when to use present perfect progressive?” I’m going to give you a simple rule that you can use. If you follow it, you’ll always create a correct sentence, even though there may be other correct ways to say the same idea:
SIMPLE RULE:
When you want to show that an action started in the past and has continued until now,
*for most verbs, use present perfect progressive, but
*for stative verbs, use present perfect meaning #1 (in other words, present perfect + a length of time).
Examples:
Betty and Barney have been eating dinner for forty-five minutes. (For most verbs, use present perfect progressive)
Wayne has been doing his Chinese homework since 7:00. (For most verbs, use present perfect progressive)
Barney has known Fred since they were little kids. (For stative verbs, use present perfect + a length of time.)
Homer has loved Marge since they were in high school. (For stative verbs, use present perfect + a length of time.)
If you want the complete story on when we use present perfect meaning #1 and when we use present perfect progressive, see “I want to know more than the simple rule! How are meaning #1 and present perfect progressive different?”
2. Using since, for, and in
We often use since, for and in with present perfect meaning #1 to show a length of time. Let’s look at each one individually.
A. Using since with meaning #1
*We almost always use since with a point in time. 1
1 Examples:
I have taught at Chabot since 1992.
since June, 1992.
since June 12, 1992.
since 10:00 a.m. on June 12, 1992.
since I moved to El Cerrito.
Sometimes you’ll hear an American use since + a present perfect clause (e.g.-- I’m so blue since you’ve been away), which is different from since + a point in time. It’s also a lot less common. If you’d like to find out more about it, there’s a brief discussion in “Since + a present perfect clause” on p104.. 1 1 Since can have another meaning; it can also mean because. For example: “Since (because) she was feeling sleepy, Lucy decided to make a pot of coffee.” This is a completely different meaning from since + a point in time.
IMPORTANT NOTE:
Since + a point in time is only used with perfect tenses. Theoretically, it can be used with any perfect tense (although we don’t use it very much with future perfect tenses. For is a lot more common with future perfect and future perfect progressive).
Examples:
Ricky has worked at the Copacabana since 1998. (present perfect)
Wayne has been studying Cantonese ever since he fell in love with a Chinese girl. (present perfect progressive.)
Melvin was crushed when he learned the truth. He had believed in Santa Claus since he was a child. (past perfect)
Mary pulled over to the side of the road for a nap. She had been driving since the sun came up. (past perfect progressive.)
John’s going to be exhausted when he gets off work tonight; he will have been working since five this morning. (future perfect progressive.)
IMPORTANT POINT TO REMEMBER: If you use since + a point of time, you need to use a perfect tense!
B. Using for with meaning #1
We use since with a point in time, but we use for with a length of time.
Examples:
I have taught at Chabot for thirteen years.
for two months.
for three weeks.
for ten minutes.
If we want, we can omit for and just say a length of time:
Examples:
I have taught at Chabot thirteen years.
two months.
three weeks.
ten minutes.
Although since + a time is only used with perfect tenses, for can be used with almost any tense. (The exception is present progressive. We almost never use time phrases with present progressive.)
Examples:
Trixie has lived in New York for fifteen years. (present perfect)
When I was young, I lived in Hawaii for two years, but now I live in California. (simple past)
Don’t cry, honey. I’ll only be in Iraq for a few months. (future)
Fred and Barney were bowling for three whole hours last night. (past progressive)
Using in with meaning #1
If we want to tell the length of time a person has not done something, then we can use either for or in. Both are okay and they mean the same thing when we use them in this way.
Examples:
You haven’t written your mother for a long time. You should write her today. She may be getting worried about you.
You haven’t written your mother in a long time. You should write her today. She may be getting worried about you.
(These two sentences mean the same thing.)
John hasn’t practiced the piano for two years, but he wants to start playing again soon.
John hasn’t practiced the piano in two years, but he wants to start playing again soon.
We only use this meaning of in with present perfect, past perfect, and future perfect.
Source: English Verb Tenses
