ch. 2 Toward(s), to, in/into, inward, outward, through, out (of), from (vs off), away (from)

9.2.3 A variation from the basic meaning: Keep from …-ing

In expressions such as stop from and keep from, the meaning of from is particularly interesting. For example, at first sight it may be difficult to see how from in (75) and (76) can mean, ⭕→.

(75) I keep away from the dog just in case what she has is contagious.
(76) How to stop a cat from clawing furniture.

Let’s first of all analyze the literal use of from in (75).
Step 1: away from the dog means: 【←dog】.
Step 2: the opposite of this is to the dog, i.e.: 【→dog】.
Step 3: keep away from the dog can be summarized as: 【NOT →dog】.

In example (76), from is used metaphorically but otherwise very much like it is in (75). That is, stop a cat from clawing furniture can be summarized as: 【CAT NOT → claw furniture】. At root, therefore, stop from and keep from include the meaning ‘not to’, and this makes good sense given that to is the opposite of from.
按：第三步只能得出 away from the dog can be summarized as: 【NOT →dog】，否则keep和stop简直没有任何作用了 ；即away from the dog和from clawing furniture是相对I和a cat这两个Subject而言的prep. + Landmark，而I keep和stop a cat应该另算，这样才符合本书的说法……protect/prevent显然同理。
（不过这样的话是不是和现代语法关于“介词词组是动词的补足语[complement]”有冲突？🐶）