It's "colleges".
No, the word alumnae is the plural form of the noun alumna, a female graduate of a school, college, or university. The plural form of the noun alumnus is alumni, male graduates of a school, college, or university.
The plural form for the noun college is colleges.The plural possessive is colleges'.example: All of these colleges' teams are in the competition.
Words have plural forms, but sentences don't. It doesn't really mean anything to say, what is the plural form of that sentence. However, the sentence does contain two nouns, sister and cousin, which could be changed to plural nouns, sisters and cousins. It is not necessary to change college, since "in college" does not necessarily mean in a specific college, just in some college.
The plural form for the noun sister is sisters; the plural possessive form is sisters'.Examples:My sisters' school is Lincoln High. Jane is in ninth grade and June is a senior.My sisters' schools are Lincoln High and Washington Community College.
There is no plural form. Do and Do not are verbs
The plural form of him, her, or it is them. (objective pronouns)
Bridges is the plural form of bridge.
The plural form of "was" is "were."
The plural form of "I" is "we."
The plural form of "is" is "are."
"Groceries" is the plural form of "grocery."
"Beliefs" does not have a plural form, as it is already plural. Beliefs is the plural form of belief.