DURATION FORM with Present Perfect 
Present Perfect with “For / Since” ("da")
I have lived in Canada for 3 years. = Vivo in Canada da 3 anni
I have lived in Canada since 2012. =Vivo in Canada dal 2012
She has studied with me for 3 months. 
She has studied with me since October. 
Function: Why do we use “For / Since”?: to measure time (usually with the present perfect sentences) and to show how long the action (that is not finished) has happened 
 Form: How do we use “For / Since”?
  [ Subject + have/has + past participle + for/since ]
I    +     have   +     lived here    +   for     + ten years.          
He  +      has    +  worked there   +   for     + three months. 
I    +     have   +     lived here    +   since  +  1996.          
He  +      has    +  worked there   +   since  +  October. 
Quick Grammar Exercise Put either for or since into the following sentences.  
 [1] I have lived in this flat___since__ 2006. [2] He has been in my class ________ 2 years. [3] They have owned that restaurant ________ I was 10 years old. [4] We have played soccer on Sunday morning ________ June. [5] My brother has been stronger than me _________ 3 years. [6] She has been here _________ 8am this morning. [7] American soldiers have been in Korea _________ 1950. [8] Christmas has been celebrated ________ 700 years. 
Remember: Since= point in time; For=periodo of time

HOW LONG + Present Perfect= Da quanto tempo...?
[1] What kind of phone do you use?   I use an iPhone 5s.   
How long have you had your phone?  I've had it since it 2013.