Not only can adults learn English or another language, but they can acquire it. I can see this in my classes, thank God.
Adults have the capability of organizing their learning process, which young learners don’t have.
Moreover they have the cognitive and metacognitive capability to acquire the language, and ways for intuition, which young leaners do not have yet.
Also they can hold human relationships that young learners cannot construct.
So I support learning and acquiring a language by adults. / Photo from: adult female with computer smiling www britishcouncil bh