ewe sheep
The singular possessive form of letter is letter's. The plural of letter is letters. The plural possessive of letters is letters'
The singular form is cow an archaic plural for cow is kine
Plural.
Correspondence is both plural and singular - a communication by exchange of letters
No. The word "letters" is a plural noun, or a present tense (third person singular) form of the verb "to letter." The singular noun "letter" can be used as a noun adjunct, as can the participles lettering and lettered.
The plural of letter is letters.
mouse/mice
Letters is the plural of letter
mice is the plural of mouse and lice is the plural of louse
mice is the plural of mouse and lice is the plural of louse
Analysis already is the singular. The plural is analyses. Note the difference in the bolded letters.
The scientific name for the backbone(s) is the plural noun vertebrae (9 letters).The singular noun is 8 letters, vertebra.