A couple

Is 'a couple of noun. ' a plural or singular?  Please correct the sentences below if any.

• That was a couple of good catches.
• Those were a couple of good catches.
• A couple of corrections was made to the document.
• A couple of corrections were made to the document.
• There is a couple of days to wait.
• There are a couple of days ot wait.
• A couple of days is very fast.
• A couple of days are not fast.

Thanks

Can anybody help me on the questions above?

Thanks a lot!

Treat couple as plural.

• That was a couple of good catches.
• Those were a couple of good catches.
• A couple of corrections was made to the document.
• A couple of corrections were made to the document.
• There is a couple of days to wait.
• There are a couple of days to wait.
• A couple of days passes quickly
• A couple of days passes slowly.