Q: Is backup a single word? I've seen it written as back-up, and as two words (back up), as well as one word. I've had discussions about whether backup is even a word at all.

A: Correspondent Jim Calloway, who sent this question, is not the first to ask it. The answer depends upon popular usage. At this time, usage denies that backup is a verb. The reason is that when you use the past tense, you add the past tense marker -ed to the first syllable, as in, “He backed up his car as far as possible.” If backup were a single word, one would add -ed to the second syllable: “He backupped the car.” Instead, to back up is like other verbs to which we add an adverb. Compare, “He climbed up the tree.”

On the other hand, backup is a noun. Webster's Third (1993) lists it, along with other compounds like backpedal and backhand. It is used in sentences like, “Attorney Smith will be my backup if I cannot appear.” Some may consider that back-up when used either as a noun or an adjective ought to be hyphenated in, for example, “John Jones is the back-up speaker for the banquet.” As stated above, popular usage decides.

When word-pairs are first introduced, they are usually written as two words: The compound off-limits first appeared in sentences as two words: “The area was off limits for non-ticket holders.” Some word-pairs remain hyphenated, but others eventually become single compound words. Hyphenation may be thought of as an interim stage in the development of a single word.

That seems to have been the case with backup. Although back is still thought of as a verb plus the adverb up, when backup became popular as a noun and adjective, it became hyphenated. And today, the noun and adjective forms are still sometimes hyphenated, although backup is correct as a single word, like pickup.

When a word enters the language with a prefix attached, like the noun co-operation, the public resists dropping the hyphen. That is why co-operation, and words like loop-hole and tie-up (“traffic jam”) are still sometimes hyphenated. Without the hyphens, pronunciation may be confusing. It has been said that feminists objected to the “sexist” word manslaughter, and would have called the crime peopleslaughter, except that the substitute could then have been pronounced peoples laughter. (The story is probably apocryphal.)

There's another question about verbs like back, which add particles (prepositions or adverbs). The adverb up is needed in backup to distinguish it from back down, back in, or back out. But some verbs take on unneeded suffixes or prefixes. One reader recently wrote to complain about the word on in the statement, “He continued on with his argument.” The verbs print and shake don't need adverbs to complete their meaning. Yet we say, “print it out,” and “shake it up.” And a lawyer recently wrote that in a topnotch economics journal article the phrase “appealed against” was used, although the verb appealed includes the meaning of against.

The redundant and ungrammatical where ... at is also prevalent. It appears both in statements and in questions: “I don't know where he is at,” or “Where is he at now?” There's no need for the word at, for the adverb where means “the place at which,” But people may add at by analogy to, “Where did he come from?” That's idiomatic, so why not, “Where is he at now?” or “Where is he going to?” Only because the first is idiomatic and the other two are not. Readers have written to criticize the redundant, “The reason why is because,” when only four words are needed: “The reason is that ....”

Q: Chicago attorney Jeffrey Liss writes, “In the local newspaper, the following quotation appeared, ‘If the landlord was guilty of violating the rule ....' Shouldn't that be ‘If the landlord was guilty in violating the rule?'” (Italics added.)

A: That's a good question, but to answer it, I'd have to see more of the language. If the additional language begins “when he ...,” the word in is preferable: “If the landlord was guilty in violating the rule when he barred the renter from entering....” However, if the omitted language was “because he ...,” the preferred word is of : “If the landlord was guilty of violating the rule because he barred the renter from entering....”

My thanks to Attorney Benjamin G. Shatz for sending me a copy of his interesting article, “Watch Out for Tricky Typos,”which appeared in the journal, “For the Defense,” in February 2007. His list of “tricky typos” included statue for statute, which was found in the “allcases” database of Westlaw in 1,485 occurrences of “statue of limitations” alone. (That error was also a perennial favorite of my freshman law students.) Other typos Mr. Shatz listed included “trail court” for “trial court” (l,272 occurrences) “untied” for “united” (481occurrences), and many more, including “pubic” for “public,”(only one occurrence).

When I proofread my own columns, I have to take care to avoid typing not for now, which causes me to say exactly the opposite of what I intended. I read a typo in yesterday's local newspaper that surely must have caused considerable embarrassment to both the reporter who wrote it and the person it involved. The article stated, “This weekend's Spring Garden Festival, in a change from last year's festival, contained few seminars, but the ones scheduled are worth nothing.” (The unintended h did the damage.)