English Quirkisms

Affect and Effect
When you affect a situation, you have an effect on it.
affect - verb
effect - noun

affect - have an effect on; influence, esp. injuriously; stir the emotions of; affect and effect, since most people make no distinction in pronouncing the first vowel of these words, the spelling is likely to be confused. affect, a rather formal word, is always a verb, meaning to influence; effect is most commonly a noun, meaning result

Blond or Blonde
The words blond and blonde come from the French and follow somewhat the French pattern. Blond (without the e) is used to describe males, mixed gender, or uncertain gender. Blonde refers to women or female gender.

In modern use, blond is sometimes used for female as well as male, but blonde is preferred for female.

Canvas and Canvass
a canvas is a strong cloth made of cotton, flax, or hemp, used to make tents and sails.
canvass - Examine carefully. Examine. Discuss.

Desert and Dessert
A desert is a landscape or region that receives an extremely low amount of precipitation.
dessert is a course that typically comes at the end of a meal, usually consisting of sweet food

Disc and Disk
Optical discs like CDs are spelled with a "c," and other kinds of computer storage media such as floppy disk drives and external hard drives are spelled with a "k."
Although there is some disagreement, Stedman's medical dictionary recommends the spelling "disc" for all medical uses. You can remember that "optical" has a "c" in it and the spelling "disc" for optical drives and biology (like your optic nerve) also are spelled with a "c."
I stored my data on a compact disc.
I have a slipped disc in my back.
Does anyone use floppy disks anymore?
The disk failed in my external hard drive.ually consisting of sweet food

Dissociate and Disassociate

Either and Or
Either" is also a singular adjective. It means one or the other, but not both. "Either" expresses one noun/pronoun doing one thing and the other noun/pronoun doing another; in this way it is a "positive" word because what is occurring is true. "Either" can be paired with "or", but not "nor".
She wanted to paint either a landscape or a self-portrait. (She wanted to paint one or the other, but not both.)
I can't remember if either Georgia or Julia wanted a doll for Christmas. (One of the girls wanted a doll, but not both.)

Farther and Further
farther denotes physical advancement in distance

further denotes advancement to greater degree, as in time

Heroin and Heroine
Heroin is an opiate drug that is synthesized from morphine, a naturally occurring substance extracted from the seed pod of the Asian opium poppy plant.
Heroine is A woman noted for courage and daring action. 2. A woman noted for special achievement in a particular field. a mythological or legendary woman having the qualities of a hero b : a woman admired and emulated for her achievements and qualities

i.e and e.g.
i.e. stands for "that is," or "in other words."

e.g. means "for example."

The Latin abbreviation i.e., which stands for id est, means that is, that is to say, or in other words. The letters e.g. stand for the Latin phrase exempli gratia, which means for example.

Neither and Nor
Neither" is a singular adjective and can be paired with "nor" in a sentence. "Neither" is never paired with "or". When using "neither" in a sentence, you are saying not the first object and not the second object are behaving in a certain way. The nouns/pronouns are in agreement with one another. "Nor" can also be used independently when negating the second part of two negative clauses.
Neither Corie nor Bob went to the play. (Corie isn't going to the play. Bob isn't going to the play.)
She said, "I don't like broccoli." I said, "Neither do I." [Neither is used here because she doesn't like broccoli, and I don't like broccoli. (You may hear people say,"Me neither," this is colloquial and not grammatically correct. You wouldn't say, "Me don't like broccoli.")]
She didn't want to sing, nor did she want to dance.

That and Which

Restrictive clauses (“that”) modify, focus and limit. Because the information they supply is essential to the intended meaning of the sentence, they are not set off by commas.
Non-restrictive clauses (“which”) do not limit the words they modify. They simply add information that otherwise would not be provided. Non-restrictive clauses are set off by commas because the information they provide is supplementary, not essential to the meaning of the sentence.

“That” restricts the reader's thought, directing attention to a specific bit of information to complete a message's meaning. “Which” is non-restrictive and introduces subsidiary rather than essential information to the meaning of the sentence.
Important note involving “which”: “Non-essential” does not mean that the information is not important or that it's not relevant. It just means that it's not essential, grammatically, to the meaning — the central understanding — of the sentence.
The lawnmower that is in the garage needs sharpening.
We have more than one lawnmower. Only the one in the garage needs sharpening.
The lawnmower, which is in the garage, needs sharpening.
We have only one lawnmower. It's in the garage and needs sharpening.
The statue that stands in the hall is on loan from the museum.
A number of statues are in the building. Only the one in the hall is on loan from the museum.
The statue, which stands in the hall, is on loan from the museum.
Only one statue is under discussion. It is on loan from the museum and happens to be in the hall.

To and Too

Too Meaning In Excess or Overly