The Complete Guide to English Spelling Rules (25 page)

C
HAPTER 23

Using
oy
and
oi

W
hile the long vowel sounds produced by
oy
and
oi
are exactly the same, there is a logical reason to use one rather than the other. There are very few exceptions.

Spelling rule #1: The
oy
is used at the end of a word:

Spelling rule #2: The
oi
is used in the middle of a word:

Note that the
oi
must be followed by at least one consonant:

Note that
oid
is also a suffix meaning
“resembling”
or
“like”
:

Very few words start with either
oy
or
oi
:

Note that many centuries ago,
oyster
was spelled
oistre.

When adding suffixes, as the
y
is preceded by a vowel the
y
is not usually changed to an
i.

Three words that retain the
y
in order to avoid the
oia
combination are
royal, loyal,
and
voyage.
The
oia
combination is very rare in English: s
equoia
and
paranoia.

C
HAPTER 24

Using
ay
and
ai

T
he long vowel sounds produced by
ay
and
ai
are exactly the same, but there is a logical reason to use one rather than the other. There are very few exceptions.

Spelling rule #1: The
ay
is used at the end of a word:

Spelling rule #2: The
ai
is used in the middle of a word:

Note that the
ai
must be followed by at least one consonant:

There are very few words that start with
ay
or
ai.

When adding suffixes, as the
y
is preceded by a vowel, the
y
is not usually changed to an
i.

Note that three words follow the rules when they take the past tense.