esperanto_story1-10, Exercise 3: The hardest claim

Model answer (check the details):

Hardest: "Nobody speaks it" (and its mirror, "millions speak it"), because the answer depends on a definition of "speak" and there is no census.

Why: speakers learn informally and at different levels; association membership counts only those who join; online course numbers show interest, not use; estimates come from supporters or from small surveys.

Evidence I would still want: a survey of learners that defines levels and samples fairly, repeated over several years; exam entries and results; attendance at gatherings over time; and independent data from online platforms on how many learners continue.

Another candidate: the Nazi-ban claim, because motives in a regime's records are mixed and records are incomplete.