present perfect

[sardine]

Hello all,
We useally say, "I have finished my homework, so let's go out to play."

Do you never say, "I finished my home work, so let's go out to play." ?

Thanks in avance.

[ruofei]

We useally say, "I have finished my homework, so let's go out to play."

Do you never say, "I finished my home work, so let's go out to play." ?

You are in a present-framed situation, hence the use of present perfect. 'just' is somehow ellipsed:
"I have (just) finished my HW, so let's go out to play"
(the action has a result in the present: now you no longer have HW to do, so you can go out)

Now, if you're refering to a situation that happened at a particular time in the past, then you can use the past simple:
"[yesterday] after I finished my HW, I went out to play"

My humble explanations...

[Tdol]

I would never say 'I finished' in this context.