I. According to the evidence.—In the evidence that a word is not simple, but derived, there are at least two degrees.
A. That the word strength is a derived word I collect to a certainty from the word strong, an independent form, which I can separate from it. Of the nature of the word strength there is the clearest evidence, or evidence of the first degree.
B. Fowl, hail, nail, sail, tail, soul; in Anglo-Saxon, fugel, hægel, nægel, segel, tægel, sawel. —These words are by the best grammarians considered as derivatives. Now, with these words I can not do what was done with the word strength, I can not take from them the part which I look upon as the derivational addition, and after that leave an independent word. Strength - th is a true word; fowl or fugel - l is no true word. If I believe these latter words to be derivations at all, I do it because I find in words like handle, &c., the -l as a derivational addition. Yet, as the fact of a word being sometimes used as a derivational addition does not preclude it from being at other times a part of the root, the evidence that the words in question are not simple, but derived, is not cogent. In other words, it is evidence of the second degree.
II. According to the effect.—The syllable -en in the word whiten changes the noun white into a verb. This is its effect. We may so classify as to arrange combinations like -en (whose effect is to give the idea of the verb) in one order; whilst combinations like th (whose effect is, as in the word strength, to give the idea of abstraction) form another order.
III. According to the form.—Sometimes the derivational
element is a vowel (as the -ie in doggie); sometimes a consonant combined: in other words, a syllable (as the -en in whiten); sometimes a change of vowel without any addition (as the i in tip, compared with top); sometimes a change of consonant without any addition (as the z in prize, compared with price; sometimes it is a change of accent, like a súrvey, compared with to survéy. To classify derivations in this manner is to classify them according to their form. For the detail of the derivative forms, see Deutsche Grammatik, ii. 89-405.
IV. According to the historical origin of the derivational elements.—For this see the Chapter upon Hybridism.
V. According to the number of the derivational elements.—In fisher, as compared with fish, there is but one derivational affix. In fishery, as compared with fish, the number of derivational elements is two.
[§ 427]. The list (taken from Walker) of words alluded to in p. [293], is as follows:—