I threw my old clothes away yesterday.
could + have + past participle
These machines work the cotton into a kind of soft, untwisted rope.
The cotton is worked into a kind of soft, untwisted rope.
Workers pick the cotton from the fields.
The cotton is picked from the fields.
My green necklace broke, so I threw it away.
could + have + past participle
People ship the cotton to textile mills.
The cotton is shipped to textile mills.
Machines twist the fibres to make cotton thread.
The fibres are twisted to make cotton thread.
Machines remove the seeds from the cotton.
Seeds are removed from the cotton.
More machines pull and twist the rope until it’s thin.
The rope is pulled and twisted until it’s thin.
I ordered these shoes online but they don't fit.
should/shouldn't + have + past participle
Last year’s clothes are too small for me now.
could + verb
I’m going to dye this white shirt a nice bright red.
should/shouldn't + verb
I've bought four T-shirts and got another one for free!
should/shouldn't + have + past participle
People use special machines to separate the fibres.
Special machines are used to separate the fibres.
How does this outfit look for the party?
should/shouldn't + verb
Textile machines clean the cotton and separate it into smaller pieces.
The cotton is cleaned and it’s separated into smaller pieces.
I don't know what to do with my old clothes
could + verb