Common_Errors_in_English_usage

Something grows exponentially when it repeatedly grows by multiples of
some factor in a rapidly accelerating fashion. Don't use the word
loosely to refer to ordinary rapid, but steady, growth.
See also "orders of magnitude."
EXPRESSED/EXPRESS
One of the meanings of "express" is "explicit": "Izaak claimed that his
old boss had given him express permission to shop on eBay for fishing
rods during work hours." Some people feel the word should be
"expressed," and that form is not likely to get anyone into trouble; but
if you use it you should not presume to correct others who stick with
the traditional form: "express permission" (or orders, or mandate, or
whatever).
EXPRESSES THAT/SAYS THAT
"In her letter Jane expresses that she is getting irritated with me for
not writing" should be corrected to "In her letter Jane says that. . . "
You can express an idea or a thought, but you can't ever express that.
In technical terms, "express" is a transitive verb and requires an
object.
EXPRESSO/ESPRESSO
I've read several explanations of the origin of this word: the coffee is
made expressly for you upon your order, or the steam is expressed
through the grounds, or (as most people suppose­­and certainly wrongly)
the coffee is made at express speed. One thing is certain: the word is
"espresso," not "expresso."
While you're at an American espresso stand, you might muse on the fact
that both "biscotti" and "panini" are plural forms, but you're likely to
baffle the barista if you ask in correct Italian for a biscotto or a
panino.
EXTEND/EXTENT
People often write "to a great extend" or "to a lesser extend." "Extend"
is a verb only, and should not be used as a noun. It's "to a great
extent," and "to a lesser extent."
EXTRACT REVENGE/EXACT REVENGE
The use of a rare sense of "exact" confuses people, but the traditional
phrase is "exact revenge", not the seemingly more logical "extract
revenge" or "enact revenge."
IN THE FACT THAT/BY THE FACT THAT
The correct phrase is "by the fact that," not "in the fact that." While
we're at it, "infact" is not a word; "in fact" is always a two­word
phrase.