I – Present perfect
The simple present perfect is used for past actions that have consequences in the present. For example, « I have lost my keys » implicates that I cannot open the door now. There is a link between the past and the present.
⚠️Don’t forget that the past participle can be irregular!
Auxiliaries with the simple present
II – Present perfect or preterit ?
⚠️ For advanced learners: sometimes the present perfect continuous is better than the present perfect