Past simple
Uses  
- Events  in the past that are now finished 
- Situations  in the past 
- A  series of actions in the past 
USE 1: Past actions that are now finished
 The first use of the Past Simple to express actions that happened at a specific time in the past. The actions can be short [1] or long [2].
 
Examples:
-   John  cut his finger last week. [1] 
-   I  went to college 3 years ago. [2] 
-   He  ate the dinner 1 hour ago. [1] 
 
USE 2: Situation in the past
 Another use of this tense is talking about situations in the past.
 
Examples:
  Before       Now
USE 3: A series of actions in the past
 The Past Simple can also be used with a few actions in the past happening one after another.
 
Example:
the grey monster was in love with the pink monster, he decided to give her some flowers but his friend hit him on his head considering him a betrayer.  
  
   | Time    Expressions | 
   | Common    time expressions in    the Past Simple are: 
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      To be
Form     regular verbs
   irregular verbs
to be
      
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 | Positive    sentences | Negative    sentences | 
   | I | was | Was    not (wasn't) | 
   | you | were | Were    not (weren't) | 
   | He/she/it | was | Was    not (wasn't)      | 
   | we | were | Were    not (weren't) | 
   | they | were | Were    not (weren't) | 
  
   | Question    form | 
   | Was    I? Were    you? Was    he/she/it? Were    we? Were    they? | 
Regular verbs
Positive senteces
we add -ED to the base form of the verb
Ex: work → worked
look → looked
when the verbs end in y:
Irregular verbs  
Positive sentences
we take the form from the second column of the paradigm.
      
   | Base    form | Past    simple | Past    participle | 
   | bring | brought | brought | 
   | meet | met | met | 
   | sing | sang | sung | 
   | take | took | taken | 
Negative and question forms (both regular and irregular verbs)
negative form
subject + did not (didn't) + base form verb
Ex: I did not go out last night.
questions
did + subject + base form verb?
Ex: Did you work yesterday?
Present Perfect
Uses
1)  Actions which happened at an indefinite (unknown) time before now
2)  Actions in the past which have an effect on the present moment
3)  Actions which began in the past and continue in the present
USE 1: Indefinite time before now
 Use the Present Perfect to talk about actions that happened at some point in the past. It does not matter when they happened.
Examples:
-   I  have passed my exam. 
-   He  has been to England. 
 
USE 2: Effect on the present moment
 We also use this tense when an activity has an effect on the present moment.
Examples:
 
 
USE 3: Continuation in the present
 We often use the Present Perfect when we want to emphasize that an event continues in the present.
 For this use in Italian we don't use “passato prossimo” but “presente” so pay attention when you translate from Italian into English!
Example:
 (Mary lavora come insegnante da più di 25 anni)
       
 teacher's note: Presen Perfect can be considered the tense that expresses experiences in your life (when you are alive) without an exact time reference.
 
  
   |     Common    time expressions in the Present Perfect are: | 
   |     Since    and For are very common time expressions used with the    Present Perfect.     We    use For with a period of time, for example:     When    talking about a starting point, we use Since, for example: | 
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Form
To form a sentence in the Present Perfect, you need:
 present simple of TO HAVE + PAST PARTICIPLE
 1. to Have
      
    | Person | Singular | Plural | 
  
    | First 
 | I have 
 | We have 
 | 
    | Second 
 | You have 
 | You have 
 | 
    | Third 
 | He/she/it has 
 | They have 
 | 
 
 2. The Past Participle
  The past participle can be either regular or irregular. -         
     | Verb | Past      Participle |       | talk 
 | talked 
 |       | explain 
 | explained 
 |  
 
      
   | Base    form | Past    simple | Past    participle | 
   | bring | brought | brought | 
   | meet | met | met | 
   | sing | sang | sung | 
   | take | took | taken | 
 Positive form
Subject + have/has + past participle
Negative form
Subject + have not/ has not (haven't / hasn't) + past participle
Question form
have/has + subject + past participle ?