Present Perfect Tense is used to show the result of an action. It is used to talk about actions that started in the past and already continue to the present. It is used with since and for to say how long an action has lasted. We can not use the Present Perfect Tense with Adverbs of Time (yesterday, three weeks ago etc…)
I
You We They |
have | already prepared | breakfast. |
He
She It Mark |
has | already prepared | breakfast. |