Tense indicates when the action or state of being occurs. Forming tenses can be simple or complicated.
Present, past, and future
The present, past, and future tenses are part of our everyday language, and as writers we should be able to use these forms with ease. The present tense indicates an action occurring now.
He calls her on his cell phone every hour.
Sometimes, the present tense is used to indicate future action.
Her plane arrives on Friday.
The past tense indicates action completed in the past.
He called her on his cell phone yesterday.
The future tense is used for action that will occur at a future time.
He will call her on his cell phone next week.
Present perfect
The present perfect tense, formed with has or have and the past participle of the verb, indicates an action that occurred in the past and has continued into the present.
I have called you for a week. (And I am still calling you.)
This contrasts with the simple past tense, which suggests an action that both began and ended in the past.
I called you for a week. (But I am no longer calling you.)
The present perfect tense can also be used when you want to emphasize an action that occurred in the past but at no definite time.
I have called many times.
Past perfect
The past perfect tense, formed with had and the past participle of the verb, indicates an action completed in the past before another action completed in the past.
After I had called you ten times, I checked your phone number.
Had called is a past action that was completed before checking the phone number, another completed past action.
In the following example, his being sober for a year preceded the accident: past before past.
He had been sober for a year when the accident happened.
Future perfect
The future perfect tense, formed with will have and the past participle of the verb, is used for an action that will be completed in the future before another future action.
By next week, I will have texted you more than a hundred times.
Texting more than a hundred times will take place before next week. In the following example, his achieving sobriety for a year will precede the future arrival of his baby daughter.
He will have been sober for a year by the time his new daughter is born.