It's "a pair of pliers". Since "pliers" is always a plural noun, you cannot use "a" with it.
It's "a pair of pliers". Since "pliers" is a plural noun, you cannot use "a" with it.
I need to buy a pair of pliers.
I need to buy a pliers.
We never use “a” before "pliers" because “a” is for one; but you can use the determiner "a pair of" to refer to a single instance of this small tool.
A pair of pliers can be used to hold a nail in place.
When talking about more than one object, you can say "two pairs of pliers", "three pairs of pliers", etc.
He bent the tips with two pairs of pliers.
Alternatively, you can use other determiners for plural nouns ("the", "some", "any", "these", "both", "several", etc.)
Some pliers are designed for cutting wire.
But omit the determiner to introduce this term in a general sense.
Pliers are typically designed to cut wire and cables.
And remember, plural nouns, like "pliers", takes a plural form of a verb. Thus, we say "pliers are" (not "pliers is").
These pliers are very versatile.
These pliers is very versatile.
Follow the same convention with the following tool names: