What is the correct form in the following sentences, "both" and "both of them"?
a) "Both of them are unique."
b) "Both are unique."
If "both" by itself already contains "both of them", so I can conclude that the first option is not correct. Isn't it?
Either one works. "Both" implies "Both of them." They are interchangeable in English among native speakers.
They can be interchangeable but it may depend on the context.
Both of them
Q: Do you want David or John to join us?
A: Both of them.
can imply a joining or grouping together, whereas
Both
Q: Salt or pepper?
A: Both please.
allows them to be thought of separately.
