CalifJim posted a long, informative response to a question about the use of the past and present perfect tense. The following paragraph is an excerpt from his posting:
>> The present perfect, however, does not "singularize", "individuate" or "particularize" an action. With the present perfect, we don't even know exactly when the action happened! What is more important with the present perfect is that the action now has some felt effect on the present. When you say "I have written a letter", in a way you are pointing to that letter and saying, "And here it is. Here is the letter I have written" -- even though the pointing and saying may be only a mental pointing and saying! The important thing is having (hence the auxiliary "have") the letter now.
Now, I understand that if I wrote a letter at some point in the past but don't know when exactly I wrote it, I have to use the present perfect tense: Hence, "Since Monday, I have taken a shower, I have written a letter and I have made a cake."
As a result of these activities, I am now clean, I have a letter and a cake. This is what CalifJim refers to in his example. But what about activities, which do not have any particular effect on the present, leaving me with no cake, clean body or letter? For example, what tense to you use when watching TV?
So while eating chocolate is clear: "Since Monday, I have eaten two pounds of chocolate." --> The chocolate is gone.
Watching TV is more complicated: Is it "Since Monday, I watched seven episodes of 'Mr. Bean'." or "Since Monday, I have watched seven episodes of 'Mr. Bean'."
The "effect on the present"-rule doesn't really work here. I would nonetheless use the present perfect tense.
Comments, ideas, suggestions? Thanks a lot!
BL