I’ve swum for an hour and I’m tired now.

[Alice Chu]

Please tell me the meanings of the second and fourth sentences.

1) I’ve swum for an hour and I’m tired now.

It means the action of swimming lasted for an hour and stopped before now. It has something to do with the present.

2) I’ve been swimming for an hour and I’m tired now.

What does the sentence mean?



3) I’ve been swimming for an hour, so I’m tired now.

It means the action of swimming lasted for an hour and stopped before now. It has a result in the present.

4) I’ve swum for an hour, so I’m tired now.

What does the sentence mean?

 

[Tdol]

Been swimming could mean that the person will continue despite their tiredness.

 

[Tarheel]

The use of "now" in those sentences is entirely unnatural. If somebody says, "I'm tired" it's well understood that he means he's tired at that moment. (For starters, it's in the present tense.)