What is the perfect aspect

The perfect aspect focuses on the completion of an action. You need to use the perfect aspect if the action is / was / will be completed by a specific time. There is usually a very concrete consequence of the action. The action happened in the past, but the result of the action affects the present or the given point in time. This specific point in time is generally determined by a time expression, adverb or a clause (by the time I turn 21). It can also express an action that started in the past, but it is still happening.

Starbucks has served the best coffee for as long as I can remember.

This sentence indicates that Starbucks started serving the best coffee in the past and it still does in the present. Also, note the clause used to express time.

In past and future tenses, the perfect aspect is used to express different timelines of events. Using the perfect aspect, you can indicate that an action happened prior to another action even if both events happened in the past. The same is true for future tenses. Using the perfect aspect, the verb can indicate that an action will happen before another one in the future.

We had been married for 10 years when he finally decided to divorce me. → being married here happened prior to the decision to divorce
She will have finished her studies by 2020. → she will finish her studies first in the future and then 2020 will come

General structure of Perfect Tenses

S + conjugated form of ‘to have’ + Past Participle of the Main Verb + O

The auxiliary verb expressing a previous event is ‘to have’. ‘To have’ is always followed by the past participle of the main verb. Note that many verbs have irregular past participle forms. You can find a list of the most frequently used irregular verbs here. Make sure to conjugate ‘to have’ to agree with the subject of the sentence. The perfect aspect can be used in all tenses: present, past and future. Put the auxiliary verb ‘to have’ in the correct form of the present, past and future tenses to form a whole expression. For example,

I have been to Bali many times.

Note that there are many verbs that have irregular second and third forms. Make sure to learn the most common ones from our list!

How to use perfect tenses

As already mentioned above, perfect tenses are frequently used with different time expression. This time expression can be an adverb or a clause. When you use a clause, it is important to make sure that the tense agrees with the timeline of the events. The event that happened in the more distant past must be in Past Perfect and the event that happened closer to our present needs to be in Simple Past. For example,

We had been friends for years when he finally admitted that he loved me.

The same logic works in future tenses. The event prior to another event needs to be put in a perfect tense. For example,

The plane will have landed by 7 am.

Take a look at the following table to see the correct form of perfect verbs in each tense:

For/since – typical prepositions of Perfect Tenses

Perfect as well as Perfect Progressive Tenses use the prepositions ‘for’ and ‘since’ very often. It is very important to note that a time adverb using for or since in the sentance can change the meaning completely. Let’s take a look at this sentance first:
I have lived in Panama.
Without an adverb it means that I used to live in Panama in the past but I don’t live there anymore. However, look at what happens when we use an adverb:
I have lived in Panama since last summer.
Since last summer refers to the starting point, meaning that I started living in Panama last summer and I still live in Panama.

Let’s look at an example using ‘for’:

My mom has worked as a nurse.
This sentance means that my mom was a nurse once but today she might have another job.
My mom has worked as a nurse for 2 years.
This means that my mom started working as a nurse 2 years ago and she still works as a nurse today.

For a detailed explanation and usage, check out the individual page of each Simple Tense here:
Present Perfect Tense
Past Perfect Tense
Future Perfect Tense