Chapter 5-8-3: The Present Perfect / Present Perfect Simple Tense
“I have eaten pasta twice in the last week.”
What is the Present Perfect?
As an overview, it can be said that the present perfect describes actions that occurred in the past, and either:
the action is now complete, but the precise time the action happened is unknown or unspecified. Time is vague and unimportant; or
the action is not complete and continues into the present (or into the future), and we know when the action started.
How to Form It
The present perfect is formed using:
[has/have + past participle].
The “past participle??”
The past participle often describes a completed action. It is commonly used in the formation of perfect verb tenses.
You’ve seen it before: it’s that third column on irregular verb charts.
So, to form the present perfect, use “has” (singular) or “have” (plural) along with the past participle to form the present perfect tense.
When to Use the Present Perfect
This tense is used to describe action that began in the past and continues into the present or has just been completed at the moment of utterance. The present perfect is often used to suggest that a past action still has an effect upon something happening in the present.
When is the present perfect used?
There are three "patterns" where the present perfect is used:
actions of duration that occurred in the past, but the exact time is not specified
actions that started in the past at an unspecified time but stopped recently
actions that started in the past but continue to the present
Examine these three patterns in the text that follows.
Actions of duration that occurred in the past, but the exact time is not specified
In this first pattern, we don’t know precisely when the action took place because time is unimportant.
The action has duration, occurring over time—it didn’t happen in a single moment.
Its start time(s) and end time(s) all occurred in the past.
Actions that started in the past at an unspecified time but stopped recently
For this pattern, there is an emphasis on the “now.”¹ The completion of the action places emphasis on the present or on the result of the action. Note the following:
the action started at an unspecified time and has already been completed; and
the action recently occurred before the present.
Actions that started in the past but continue to the present
Unlike the previous two patterns, this time we have a good idea of when the action started:
the action began at a (known) time before now and continues into the present or may even continue into the future; and
this pattern only works with certain verb types.
Restrictions
Specific time
In the first two patterns above, you should know that:
you cannot use the present perfect with specific time expressions (yesterday, one year ago, last week, when I was born, when I lived in Montreal, at that moment, on that day, etc.).
You cannot use the present perfect with dependent clauses (also called "subordinate clauses") that are preceded by subordinating conjunctions that refer to time (after, as, as long as, as soon as, before, once, 'till, until when).
You CAN use the Present Perfect with nonspecific expressions (ever, never, once, many times, several times, before, so far, already, yet, in the last week, etc.).
Reference to non-existent objects
The present perfect is only used for subjects that still exist (i.e. it would be a faux pas to talk about someone that has passed away in the present perfect).
Watch out for these restrictions—instructors love to test students' knowledge of this on summative assessments.
Scenarios
The present perfect verb tense can be confusing to English learners. For some people, it is easier to think of how the present perfect is used in a variety of scenarios:
Help with "Specific" Versus "Unspecific" Time
Knowing when a time is specific or unspecific can be difficult. Take a look at the following examples and have a discussion with someone if you have trouble seeing the difference in time between the specific and unspecific columns.
Each of the highlighted compound verbs in the following sentences is in the present perfect tense.
They have not delivered the documents we need.
This sentence suggests that the documents were not delivered in the past and that they are still undelivered.
The health department has decided that all high school students should be immunized against meningitis.
The writer of this sentence uses the present perfect in order to suggest that the decision made in the past is still of importance in the present.
The government has cut university budgets; consequently, the dean has increased the size of most classes.
Here, both actions took place sometime in the past and continue to influence the present.
The heatwave has lasted three weeks.
In this sentence, the writer uses the present perfect to indicate that a condition (the heatwave) began in past and continues to affect the present.
Donna has dreamt about frogs sitting in trees every night this week.
Here, the action of dreaming has begun in the past and continues into the present.
The Present Perfect in Research
When discussing a previous study with results that are still relevant, use the present perfect tense (for example, “have shown” or “has been shown”). This emphasizes the fact that the study was conducted in the past but its results still apply to the present.
Flouride has been shown to reduce cavities.