These illustrations of
our
the
use of the word “can” should be supplemented by illustrations showing the variety of uses we make of the terms “forgetting” and “trying”, for these uses are closely connected with those of the word “can”.
Contemplate
Consider
these cases: a) Before, B had said to himself the formula, now, “He finds a complete blank there”. b) Before, he had said to himself the formula, now, for a moment he isn't sure “whether it was 2n or 3n”. c) He has forgotten a name and it is “on the tip of his tongue”. Or d), he is not certain whether he has ever known the name or has forgotten it.