Is there a simple and clear way to explain the difference between past simple and present perfect?

Question

I read (or do I say "have read"?) many rules for when to use the present perfect. I found them complex and hard to understand (or do I say "have found"?). I am finding it hard to apply these rules in real sentences.

Is there a simple and clear way to explain the difference between past simple and present perfect? If there is a simple explanation, please tell it! If there is no simple explanation, please tell why it is so complicated. Maybe if I knew why there is no simple explanation, that would help me understand what work I need to do in order to learn the difference.

Answer 1

Short answer: Yes

The difference is that the past tense means the action happened at some specific time in the past, and the present perfect means the action happened at an unstated time during a certain time interval that started in the past and continued to the present—maybe more than once during that time interval, depending on what you're talking about.

This action occupied the entire time interval from 1997 until now, and will probably continue:

Brenda has worked at Merriam-Webster since 1997.

This action occurred sometime during the speaker's life so far, perhaps many years ago, perhaps recently, perhaps more than once:

I have seen war.

This action occurred at the very end of the time interval (the time interval is that of the whole race):

Jones has won the race!

Long answer: No

The reason this topic is hopelessly complicated is because reality provides an infinity of different situations, and what time interval is reasonable to talk about varies for each situation.

For example, the time interval for the following question starts at roughly 11:00 a.m. this morning:

Have you eaten lunch?

The question literally means, "During the part that has elapsed so far today of the daily time interval when people normally eat lunch, did you eat lunch?" If you already ate lunch, then you probably don't want to go to lunch now; if you did not already eat lunch, then you might be interested in going to lunch with the speaker now. A person wouldn't ask that question after the middle of the afternoon, because that would be too much later than the normal time to eat lunch. The question leads you to think of the time period for lunch as a sort of window of opportunity that is still open, and asks whether that opportunity has already been exercised.

There's another source of endless complexity: the fact that you are referring to a time interval influences the way a listener understands the verb after have as well as the other words in the sentence.

For example, this sentence means that Chris performed the duty of phone-answerer last week, and answered the phone many times:

During the past week, Chris has answered the phone.

Using the perfect tense suggests that you might mean that the action fills the entire time interval, so the above sentence leads a listener to understand answering as performing a week-long duty to answer the phone whenever it rings. (This would probably be at a business.) Also, it would be strange to speak of a single instance of answering the phone in the present perfect if it happened at some unspecified time during the past week. If Chris answered the phone four days ago, the phone call is surely over by now.

The next sentence probably means that Chris answered the phone once. But it could also mean the same as the previous sentence:

During the past week, Chris answered the phone.

The reason it could mean the same as the previous sentence is the time interval is explicitly spelled out, and answering can still be understood as performing phone-answering duty, regardless of the tense. The past tense doesn't suggest that the action filled the time interval, so it doesn't suggest the “week-long duty” interpretation as strongly as the present perfect. But the past tense doesn't contradict that interpretation, either.

I spoke.

I have spoken.

The first of the above sentences just means that you said something. The second one means that you have said everything you have to say, and probably that you don't want to listen to or address any objections. Because the present perfect suggests a time interval that ends at the present moment, it can suggest that an action filling that time interval is now complete and will not continue. Obviously, though, that's not the intended meaning of the earlier example of someone working at Merriam-Webster since 1997.

Here's an example that follows the basic principle plainly, but is still subtle:

I wrote two novels in 2009.

I have written two novels. [The time interval is the speaker's whole life so far.]

I have written two novels in 2009. [Ungrammatical, because 2009 is over. But this would be grammatical if said during 2009.]

I have written two novels this year. [This is OK, because this year is still present.]

Yet another use of the present perfect is to establish the time frame for a news story. “Until now, most efforts to capture carbon have been expensive, in dollars and in energy.” The past tense (“were expensive”) would mean the same thing, but the present perfect suggests that the rest of the story will describe how that technology is now changing. It leads the reader to expect that the time period covered by the story will be very broad, on the order of years. Beginning a news story in the past tense suggests a very short time frame.

You just have to learn through experience to understand why people sometimes want to refer to a time interval rather than just the specific event. And you learn to infer what that time interval is, since it's usually implicit. Eventually it becomes effortless, but no simple rule could ever cover all situations.

Answer 2

PRESENT = now / PERFECT = 100% or complete or finished.

PRESENT PERFECT must have relationship with "now" and "100% status" at the time of speaking.

That's why we say "PRESENT PERFECT"

It has four types of main usage.

1. Experience

I have been to the United States before. (Now 100% of "experience")

2. Continuation(1. present perfect, 2. present perfect progressive(used when emphasized))

I have studied English for 10 years / since 1998 (Now 100% of "continuation of 10 years of studying English")

I have been studying English for 10 years / since 1998 (emphasis on continuation by 'present perfect+progresive')

3. Result/Consequence

I have lost my key. (Now 100% of result/consequence of"not having the key now (as a result of losing))"

4. Completion

I have just finished my homework. (Now 100% of "completion of your homework")

Remember that PRESENT means NOW and Perfect means 100% (100% NOW)

'experience' goes well with preposition 'before'

'continuation' goes well with preposition 'for/since'

'completion' goes well with preposition'just/already/yet'

'result/consequence' goes well with verbs 'leave/go/lose' and implies current status as a result of something or some fact.

PAST TENSE MEANS SOMETHING WAS DONE IN THE PAST.

I lost money. (We know that you lost money in the past. We don't know the exact time because there is no 'time adverb' like yesterday.)

I have lost money. (We know that you lost money and you don't have it NOW. Present perfect implies you have not money NOW and this fact can have some impact on your future action because you don't have it NOW. We don't know the exact time when you lost it. The focus is NOW you don't have it.)

Remember PRESENT PERFECT has relationship with NOW, something is PERFECT.

That's why it is called "PRESENT PERFECT"

Answer 3

Focus on your purpose.

Use simple past to:

• describe a past action that ended in the past. (I read an article last week.)

• describe an event at a specific time. (I tried the quiche at Mary's party.)

Use present perfect to:

• describe events that started in the past but continue at least into the present. (I have found it hard to understand. -- i.e. I still do)

• describe an action that has occurred in the past and will occur again (I have gone running every day this week. -- I will again)

• describe an experience at an unspecified time in the past. (I have tried the quiche. It was great.)

• describe a recently completed event in combination with the word "just." (I have just tried the quiche and I am full.)

Answer 4

The fundamental difference is this:

Past Simple: When the speaker has in mind (consciously or unconsciously) an ending time boundary for the state, action, event, etc, that the verb names or “is talking about”, or such a terminal end boundary for a time period in which such is anchored, the preterite (simple past tense) is used. The time period or periods may be implicit or explicit.

Something that ended and occurred in a time period that has ended at the time of utterance.

Present Perfect: When the speaker has in mind that the state, action, event, etc, has no ending time boundary, or does not wish to convey it, or (sometimes) that the consequences or importance of the state, action, event, etc, the present perfect is used.

Something that occurred in the past but in a relevant time period whose termination is not marked.

It is complicated because we might conceptualize something in various ways, for example the meaning or sense of a word or phrase, or how the speaker is thinking about time intervals and how they interrelate.

If I want to convey that I was born, I will very likely say “I was born [+ (optionally) more]”, not “I have been ...” nor “I am” (though both of the latter are possible). The way that we think about the concept, the meaning of the word, is most responsible for this. The consequences of the event are enduring, and the event unsurprisingly remains important to me, but we nearly always think of birth as an event with an end: Once we’ve been evicted.

Someone would be likely to say “I have been baptized”, although if we imagine seeing a baptism in a movie, say, it may seem just as clearly an event with an end. Yet, it is often conceptualized differently: as an event which marks a lasting (perhaps eternal?) transformation.

If we reflect on how these two things are and can be similar, and question a bit deeply, we will find complexity. Is not birth also a transformation with important consequences?

Thus we gain insight into the fact that the human mind perceives and interprets a very complex and very mysterious world in ways that we often take as simple truths about reality.

(Much of this idea was discussed or alluded to in Ben Kibitz’ answer; I will return and see if I can improve on this answer.)

The linguist and scholar Noam Chomsky often says that modern science was born when Galileo and his contemporaries engaged in “a willingness to be puzzled by simple things”. It was once virtually universally obvious that the sun revolves around the earth. The classical Greeks, Aristotle, explained that steam rises and rocks fall to the ground “because things seek to go to their natural place”.

So it is today for most of us with human thought and language: Words do not “refer” to things in the real world. What we call “grammar rules” are not used by the mind-brain to comprehend and produce language. They are attempts to describe aspects of what we do when we externalize thought.

How we do that remains in large part mysterious and may forever be.

Consider: If we hear “a brown house”, how do we know that it’s brown on the exterior? This is not taught, yet 5 year olds know it.

What is a river? We “know”, yet there’s much we can’t explain. If we look away from a river and look back, its “essence” (perhaps) is gone. The water has flowed past and has been replaced. Yet it’s the same river. If it becomes 1% pollution, it’s still a river. 99%? Still. 100%? What if someone throws a teabag in it? Does it carry/contain water or tea?

Ideas from Chomsky. See for example, https://youtu.be/XNSxj0TVeJs. Search “Chomsky language” for many more. He uses somewhat high vocabulary and some of what he says requires some background to understand, but contrary to many, most I’d say, academics/intellectuals, his speech is clear; at least not deliberately designed to be obscure.

How to “learn” to use them? Don’t study them! Unless you find grammar to be a compelling area of inquiry for its own sake.

Just listen to and read things you can easily understand and that you truly enjoy. Attend to meaning, not form. Our brains use their own systems, abstract and unconscious, to build a mental representation of a language. We don’t know enough about how this works to “help” it. Humans were “designed”/evolved to acquire language and we cannot help but do it if we receive input that’s interesting and understandable.

Even the simple past is not simple.

Consider “You’re already going to class? I thought it started next week.” Is “started” the simple past tense there?

More: beniko-mason.net sdkrashen.com Bill VanPatten podcasts facebook.com/groups/storylistening

Answer 5

Yes, there is a simple differentiation.

“I have done” describes me (by saying that I have the property of {having done {the thing in question} }).

“I did” makes a historical statement about the past.

(Source: a book I read once; no idea which one.)