Singular: John is speaking to Mary.
He -----------> her
(she or it) (him or it)
Plural: John and Peter are speaking to Mary and Jane.
They ---------> them
3 magazines - They are French magazines. Give them to me please.
In simple sentences put THEY before the verb
put THEM after the verb
EACH OTHER: Mr. Suzuki is speaking to Mr. Brown.
+
Mr. Brown is speaking to Mr. Suzuki.
=
Mr. Suzuki <-------------> Mr. Brown
Mr. Suzuki and Mr. Brown are speaking to each other.