Plural of Bias

The Quick Answer

The plural of "bias" is "biases." The plural form with a double s ("biasses") is obsolete.

The Plural of Bias

The plural of "bias" is "biases." In other words, the noun "bias" forms its plural in a standard way. The "es" ending is not pronounced "eez" as with "analyses" and "oases" (from "analysis" and "oasis"). Also of note, "biasses" (an old form of the plural with a double s) is now obsolete.
  • At the end, ignorance is the source of biases. If we cure that, there's nothing to fear and hate. (Musician Daryl Davis) correct tick
  • I'm not staid and unbiased here. I have certain biases I want to convey, and if you disagree, that's fine. (Newsreader Neil Cavuto) correct tick
The noun "bias" adheres to the standard rules for forming the plurals of nouns in English (shown in the table below).

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The Standard Rules for Forming the Plurals

The table below shows the standard rules for forming the plurals of nouns in English.
Type Example of Type Forming the Plural Plural
Most Nouns lamp
scythe
add s lamps
scythes
Noun Ending s, sh, ch, x or z box
dress
bias
add es boxes
dresses
biases
Nouns ending [consonant] o zero
tomato
add either s or es
(There are no rules for this - you have to know.)
zeros
tomatoes
Nouns ending [vowel] o patio
ratio
add s patios
ratios
Nouns ending [consonant] y story
penny
change the y to an i and add es stories
pennies
Nouns ending [vowel] y donkey
chimney
add s donkeys
chimneys
Nouns ending f or fe dwarf
hoof
ves and/or s
(There are no rules - you have to know.)
dwarfs
hooves or hoofs
Nouns ending is oasis
diagnosis
change the "is" to "es" oases
diagnoses
Exceptions man
louse
some nouns undergo a vowel or letters change men
lice
More exceptions salmon
sheep
some nouns do not change at all salmon
sheep
Foreign rulings fungus
medium
some nouns adopt foreign rulings fungi
media
Read more about English spelling rules.

Why Is There Confusion over the Plural of Bias?

"Bias" looks a little a like "analysis" and "oasis," both of which derive from Greek. The plurals of "analysis" and "oasis" are "analyses" and "oases" (pronounced with an "eez" ending), and this leads to some mistakenly giving "biases" a similar "eez" ending. "Bias" does not derive from Greek, and it does not end -is.

The old plural "biasses" is now obsolete. [evidence]
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This page was written by Craig Shrives.