Cladistically apes are old world monkeys, as a branch of Simiiformes/Simians.
In casual conversation and scientific tradition, most people prefer to maintain a distinction between the two groups because they’re referring to family characteristics and, in the greater social subtext, human ancestry. There is no actual scientific basis for excluding apes from the label of monkey beyond humanity’s desire to feel special and to make evolution deniers feel dumb.
That said, that’s a valid reason to continue using the distinction. If they try to argue the point just point out that they’re admitting to the existence of evolution in doing so.
Tl;Dr all apes are now considered monkeys, but not all monkeys are apes
TECHNICALLY INCORRECT BY MODERN STANDARDS
Cladistically apes are old world monkeys, as a branch of Simiiformes/Simians.
In casual conversation and scientific tradition, most people prefer to maintain a distinction between the two groups because they’re referring to family characteristics and, in the greater social subtext, human ancestry. There is no actual scientific basis for excluding apes from the label of monkey beyond humanity’s desire to feel special and to make evolution deniers feel dumb.
That said, that’s a valid reason to continue using the distinction. If they try to argue the point just point out that they’re admitting to the existence of evolution in doing so.
Tl;Dr all apes are now considered monkeys, but not all monkeys are apes