Information not in the textbook that students may want.
Somebody asked for English letter frequencies in class today. This is the average number per 100 letters. (Source.)
A 8 B 1 C 3 D 4 E 13 F 3 G 1 H 6 I 7 J - K - L 4 M 2 N 7 O 8 P 3 Q - R 6 S 6 T 9 U 3 W 2 X - Y 2 Z - V 1