One is a codex; more than one are codices. (This is similar to index and indices.)
Bridges is the plural form of bridge.
"Beliefs" does not have a plural form, as it is already plural. Beliefs is the plural form of belief.
There is no plural form for the word, countries. This word itself is a plural.
The plural of "she" is "they", so the plural of "she had" is "they had".
There is no plural form of pupae. Pupae is the plural form of pupa.
The noun codex has the plural codices.(Plural is formed in the same way as index, which has plurals indices and indexes.)
It is the plural of the word "codex" which means something bound like a book.
Bridges is the plural form of bridge.
"Groceries" is the plural form of "grocery."
There is no plural form for the word, countries. This word itself is a plural.
"Beliefs" does not have a plural form, as it is already plural. Beliefs is the plural form of belief.
The plural form of "meter" is "meters."
It has no plural form.
The plural form for the noun sergeant is sergeants; the plural possessive form is sergeants'.
The plural form of rung is rungs.
The plural form of mouth is mouths. The plural form of month is months. The Mounth is a range of hills in Scotland and does not have a plural form.
The order of the "Dragon Codex" books by R.D. Henham is as follows: "Brass Dragon Codex" "Bronze Dragon Codex" "Red Dragon Codex" "Black Dragon Codex" "Green Dragon Codex" "Silver Dragon Codex" "Gold Dragon Codex"