"When they are used properly" what is the grammatical name and it's function?

This makes no sense to me. Please clarify.

Please the remaining sentence.I mean the statement is meaningless

The phrase "when they are used properly" is known as a subordinating conjunction clause. It serves the function of introducing a dependent clause that depends on the main clause to make complete sense.

To identify this grammatical structure, here's what you need to look for:

1. Subordinating Conjunction: In this case, the subordinating conjunction is "when."
2. Subject and Verb: The dependent clause "they are used properly" contains a subject "they" and a verb "are used."
3. Incomplete Thought: The dependent clause cannot stand alone as a complete sentence because it relies on the main clause for clarity and meaning.

Overall, subordinating conjunction clauses like "when they are used properly" contribute to complex sentences by connecting dependent and independent clauses.

It makes no sense to me