Regular and irregular.

58. _What is a Regular derivative?_
One that is formed by the addition of affixes without changing the
letters in the primitive part (except final _e_ silent).

59. _What is an Irregular derivative?_
One in which the letters of the primitive part are changed.

60. _In using Affixes, what rule should be observed?_
The affix and root should be from the same language.

61. _Is the same rule to be observed in forming Compound words?_
It is.

62. _What is a Mongrel compound word?_
One formed contrary to the rule.

63. _Give an example._
Cable-graph and cable-gram.

64. _What are Barbarisms?_
Same as mongrel.

65. _When use the hyphen in Compound words?_
When they are not permanently compounded.

66. _What is an Obsolete word?_
One gone out of date.