ら
Usage
The plural marker ら is often used with demonstrative pronouns and certain personal pronouns. Personal pronouns with ら are not used in situations where politeness must be shown.
Examples
これらの問題についてもっと話し合ってみる必要がある。
It is important that we talk about those problems with each other.
彼らがいっていることはよく分からない。私たちの考えに反対なのだろうか。
What they are saying I usually don't understand. Are they opposed to our ideas?