11.   Some had to learn by trial and error.

12.   Technical and functional expertise, in addition to hierarchy provide the basis for managerial authority People learn by being trained.

13.   The past does not burden the present - but you learn by it, and do not repeat your mistakes.

14.   These are things we learn by trial and error.

15.   They learned by facing real problems and real consequences.

16.   What is important is to learn by our mistakes soas to avoid future problems.

17.   Children used to learn by repetition.

18.   Children learn by copying.

19.   It was all done in the heat of the moment and I have certainly learned by my mistake.