5. Never use he, it, this, him, her, their, them, that, those, which, whose, or the like, without looking at them from every angle to make sure that they refer to a single word. If they refer to a whole statement or to two or more possible words, they are used wrongly. The addition of a noun will usually fix the meaning. Suppose you were to receive a message with this sentence in it:
The platoon leader assigned to one squad the wrong objective, and it delayed the firing.
Grammatically, the objective delayed the firing. Logically, either the act of the platoon leader or the squad delayed the firing. You make out by re-reading the whole message that it must have been the mistake of the platoon leader which delayed the firing. But in the meantime you have lost three minutes, and the government has lost that much efficiency.
And this or which in place of “and it” in the message would have made the sense no clearer. But and this error, or which error, makes the meaning unmistakable.
6. Never use a participle without inspecting it to see that it does not dangle—that it refers to the subject of the sentence rightly. Example:
“Looking over the crater, the periscope of the enemy was seen to turn.”
What this sentence really says is that the periscope was looking over the crater—a very possible happening. But all circumstances connected with the idea, after a series of mental deductions on the part of the reader, reveal that the writer had been looking over the crater at the periscope. The commander who received this information might have been led to believe that the periscope was situated in the crater. At least he was delayed, if not misled.
7. Do not use and except where necessary. Usually, when we connect clauses with it, we do not mean and, but some more expressive word such as because, whereas, when, etc.
8. Do not use any word which might not mean the same thing to any probable recipients, or might not commonly be understood. For instance, to a southerner evening means something different from its significance to a northerner, and to an Englishman clever has not the American meaning. Watch the words which have local standards.
As to Phrases and Clauses.