Hello,
I was wondering if there’s a difference between opens and opens up, for example:
He opens his eyes.
He opens up his eyes.
Thank you!
No. “Up” is often useless, as it is here.
When “open up” is idiomatic, there is a difference.
The singer opened up about his rumored affairs. - To address candidly
Sometimes it seems the difference is just one of formality.
“Clean” sounds a bit more formal to me than “clean up,” for instance. The latter is different from the former in a metaphorical sense, though. We rarely clean messes unless we mean it literally.