Q:What is the proper use of historic vs. historical. Is it a “historical opera house” or a “historic opera house”?

A:The correspondent, John Hiskes, submitted this question, which others have also asked. The answer depends on whether the opera house mentioned is one that is famous in history or one that merely existed in history. The distinction is between “famous” and “old.”

I receive numerous questions about these two adjectives and other pairs of words that I call “confusing pairs” in my books on language. Some pairs that used to pose a problem no longer do, simply because one member of the pair has virtually disappeared. For example, there once was a distinction between the words loan and lend. If you are old enough to name the tunes you hear in elevators, you will recall when only lend could be a verb. You could not loan anyone anything. You could lend a person something, and when you did, the receiver possessed a loan. The word loan was the noun; lend was the verb. But the verb lend has disappeared, except in the language of fuddy-duddies like me.

Another such pair is lie and lay. Language perfectionists still require lie to be used as an intransitive verb (a verb that does not have an object). One lies down, but lays a book on the table. You cannot, grammatically, lay down, but now almost everyone does, although sticklers on usage wince when they hear it. The result of making lay an intransitive verb as well as a transitive verb has made the verb lie useless in that context.

The nouns enormity and enormousness used to provide a nice contrast. Something that is exceedingly large is enormous. The noun enormity describes something that is excessively wicked or outrageous. There is no adjective for enormity. So to describe something merely excessively large, the proper noun is the admittedly cumbersome enormousness. Perhaps that is why it has almost disappeared, and with it that handy contrast.

The same problem has occurred with the adjectives famous and notorious. Tele-vision's talking heads seem to be unaware that these are drastically different adjectives, and they substitute notorious for famous, although the former means you have done something dishonorable and the latter means you have done something honorable. The adjectives prevalent and widespread have had the same fate. You have to be really old to recall when calling something prevalent meant that it was unfortunate as well as widespread. Traditionally, disease was prevalent, but good news was widespread. Dictionaries now define the two adjectives as syno-nyms, and another contrast is gone.

There are many other confusing pairs, such as perspicuity/perspicacity, fragrant/blatant, flaunt/flout, flounder/founder, and torturous/tortuous, which even some lawyers confuse. If you have questions about these, or others you believe were misused, let me know.

Q:A common word that often sounds like a speed bump in the middle of a sentence is the pronoun that. When can it be omitted and when must it be used?

A:Illinois attorney Fred Baird, who asked this question, is right: when that is un-necessary, it acts like a speed bump in a sentence, so it should be omitted when possible. The same can be said of the pronouns who/whom and which. In each of the sentences below, delete them along with the immediately following language:

But even when the relative pronoun that is grammatically unnecessary, it is sometimes stylistically necessary, as in the following sentences:

You may have had to read these sentences twice to understand them because without the pronoun that the second noun seems to be the object of the verb, not a new clause.

In the January MAILBAG, reader Roberta Conwell objected to the preference for the pronoun he instead of they ( in my October column). As usual, on the subject of the “sexist he,” others have written expressing objections to her objection. Chicago attorney Michael W. Rathsack argued that when representing someone as counsel, your language is most forceful if it flows naturally, not when you choose politically correct usage that distracts attention from the point you are making. Therefore Attorney Rathsack uses both he and she naturally.