The technical term for avoiding one grammatical trap only to fall into another is hypercorrection. Just being aware of some of these traps can help to avoid them, and the judgment that sometimes comes with stumbling over language problems.
Hypercorrections: Are you making these 6 common mistakes?
Seldomly is a perfectly logical adverb form, but it has been labeled “archaic” or “rare” in our dictionaries for over a century (our 19th-century editions didn’t even enter it). Seldom is itself an adverb (“We seldom go out on weeknights”), making the -ly form redundant and unnecessary. It has been out of standard use for so long that it is rarely encountered in publications with national readership, but it still sometimes pops up:
And there are the requisite pool and tennis court, which are seldomly used.
—The New York Times, 6 July 1997
Apple is wise enough to introduce new colours so seldomly that fans go into meltdown each time a new hue is inducted into the fold.
—The Telegraph, 22 September 2015
Adverbs that are not formed with -ly are called flat adverbs, and are perfectly correct and idiomatic: think of drive safe and sleep tight
A 'whom' too far
It sometimes seems that whom and whomever are now simply used when people want to sound formal—whether correctly deployed or not. Sometimes the “correct” form sounds very stuffy and unnatural:
Whom did you speak to? (”You” is actually the subject of the sentence, and “whom” is the object of “to”)
We weren’t sure whom to hire. (”We” is the subject of the sentence, and “whom” is the object of “hire”)
More commonly, we substitute who for whom in these situations:
Who did you speak to?
We weren’t sure who to hire.
Very few people will notice or object to substitutions of who for whom such as these—but going the other way might get you into trouble. The following hypercorrections substitute whom or whomever where who or whoever is called for:
Whom shall I say is calling? (This is like saying “I shall say him is calling” instead of “I shall say he is calling.”)
The prize is for whomever guesses the correct number of peanuts in the jar. (The entire clause “whoever guesses the correct number…” is the object of “for,” and “whoever” is the subject of that clause.)
They’ve pledged to find whomever is responsible. (”Whoever is responsible” is the clause that is the object of “find.”)
We can provide help for whomever may need it. (“Whoever may need it” is the clause that is the object of “for.”)
Between you and I
Between you and me, there seems to be some confusion about pronouns when we use compound subjects (“you and me”). Though nobody is certain why such confusion exists—such errors are nearly impossible for native speakers of most languages—it may have to do with the idea that me seems more emphatic (and less polite and fancy-sounding) in some situations than I, and that the error is a hypercorrection.
When we use compound subjects, the rules for pronoun use don’t change, but it frequently seems that there is more ambiguity about whether to use I or me. We sometimes hear sentences like:
Me and my friends went to the movies.
You and me could grab some lunch.
But for subjects, I is always correct, and it’s preferable to say things like:
My team and I will be at the meeting.
Your sister and I are going swimming tomorrow.
For objects, me is always correct:
Come to lunch with Mary and me.
For my roommates and me, tomorrow is easier.
You can check to see if you’re correct by eliminating the compound subject: for “Come to lunch with Mary and I,” remove “Mary,” and you get “Come to lunch with I,” which your ear will tell you is wrong.
We hyphenate modifiers for clarity: a “large-animal veterinarian” might be different from a “large animal veterinarian.” The simple rule for hyphenation with an adverb ending in -ly, as stated in The Chicago Manual of Style, is as follows:
Compounds formed by an adverb ending in ly plus an adjective or participle (such as largely irrelevant or smartly dressed) are not hyphenated either before or after a noun, since ambiguity is virtually impossible. (The ly ending with adverbs signals to the reader that the next word will be another modifier, not a noun.)
As with so many hypercorrections, the hyphen following an -ly adverb is essentially redundant, since the word’s spelling signals that it is modifying another. Nevertheless, we do see such errors:
And second, these same members are now openly threatening a revolt against Boehner through a rarely-used procedural maneuver that could—conceivably—oust him from power.
—The Atlantic, 2 September 2015
"They feel bad that people are never told the truth," said Bocaranda, wearing a newly-made T-shirt proclaiming "I don't know" to satirize the furor over his reports on Chavez's health.
—Reuters, 8 March 2012
A widening investigation into South Korea’s Lotte Group has plunged the country’s fifth-largest conglomerate deeper into crisis, derailing a blockbuster initial public offering at the heart of a closely-watched corporate restructuring.
—Wall Street Journal, "Deals of the Day," 13 June, 2016
The -ly ending for a modifier is elegant and sufficient. No hyphens need apply.
Assuming that all final consonant sounds in French are silent
Pronouncing words borrowed from French can be tricky, especially those with a silent letter at the end. This can lead to an error of omission for other words that seem to share this pronunciation, but don’t. While it’s true that many words in French end with a silent \s\, \r\, or \t\ following a vowel, that doesn’t mean that all terminal consonant sounds in French are silent.
Similarly, the prix in prix fixe ends with a silent letter (\PREE) but the fixe does not (\FEEKS). A helpful hint is the final e in words like grâce, fixe, haute, bouillabaisse, and vichyssoise; this tells you to pronounce the final consonant. (As a rule of thumb, the \s\ in French is silent only when it is the last letter of a word.)
Saying \zh\ instead of \j\ when pronouncing words from a foreign language
When words that include a \j\ sound look like borrowings from a foreign language (usually because they are), English speakers sometimes substitute \zh\ for the \j\ sound, probably because \zh\ seems somehow to be a more correct foreign sound than \j. This reflex is based on fact: in English we don’t find \zh\ in monosyllable core vocabulary words (though we do find \j\ in words like “job” or “bridge”), so it “sounds” foreign and therefore more “authentic” to many ears.
We only find \zh\ in polysyllabic words from the Latin-based vocabulary that entered English through French, like vision or pleasure or in more recent French borrowings like beige or garage.
Sometimes we even hear people use \zh\ in English words like misogyny, likely under the perception that fancier words should have \zh\ instead of \j\.