Simple Past vs. Present Perfect

 

• Simple Past vs. Present Perfect

• You can use past simple AND present perfect for past actions.

  
  

  Use past simple for actions at a specific time in the past.

  Use present perfect for actions at an indefinite time in the past.
• I visited Mexico three times last year.

  (Past simple)

  I have visited Mexico three times.

  (Present perfect)

• Adverbs of Time

• 
• Use adverbs of time for when actions/events happen. Adverbs of time never change form.

  
  

  She hasn't finished cooking dinner yet.

  Has the party already started?

  
  

  Use never, ever, already, and just in the middle of a sentence.

  Use yet and before at the end of a sentence.

Source : Alison