Here are a couple common usage blunders we see quite often.
Don’t use insure unless you are talking about insurance. You might tell your teenager,
“We have to insure your new car.”
Ensure is the verb you want to use to promise that a certain result will come about. You would never say “ensure you.”
“The ropes were in place to ensure the safety of the workers.”
Assure is the verb you use to encourage or affirm confidently. Assure relates more to people and communication. You assure people.
“I assure you, the check’s in the mail!”
Allude is often confused with elude. At Peak Science Communications, I allude to an article or journal, but I elude Nikole when I have made a mistake. It is also worth noting that allude and refer have different meanings. When I make an allusion, it is vague or indirect; a reference is specific.
Data versus Datum, What a Conundrum (or is that conundra?)
Data is the plural of datum. Where you use this word will dictate how much of a stickler you need to be to the rules. In everyday usage, it has become commonplace to use data as a mass noun with the singular form. Mass nouns are nouns that cannot be counted, cannot be used with an indefinite article such as a or an, and work with phrases like too much or not enough (e.g., I have too much work and not enough time.)
Most style guides, however, require that data be used as a plural noun:
The data were compiled into a report to be edited by Peak Science Communications.
Effect is usually used as a noun where the word “result” could stand in its place.
“Her upset stomach was an effect of dinner the night before.”
Affect is usually used as a verb where the word “influence” could stand in its place.
“The debates will affect the way people vote.”
Etc. is an abbreviation for et cetera, literally meaning and the rest. Etc. is used for “and other things”, and at times, “and other persons”, although et. al (literally and others) is preferred in lists of persons.
Farther and further are the same according to the Merriam-Webster dictionary, but some style guides point out a distinction—farther modifies distance while further acts as a time or quantity modifier.
Less and fewer should not be used interchangeably. Less modifies collective nouns (nouns that define a group of people, animals, or things and appear in the singular form) and mass nouns. Less also pertains to amounts, degrees, and value. Fewer modifies plural nouns and pertains to numbers and things that can be counted.