Cuspis is singular. The plural form is cuspes or cuspises.
The plural of the proper noun is Carolinas.
esophagogastroduodenoscopies is the plural form
The plural form of the name Castillo is Castillos.A proper noun is always capitalized.
The plural and possessive of the abbreviation works better if the acronym is used: MD (no periods) or the title spelled out: Medical Doctor.The plural for of the acronym MD is MDs.The plural possessive form is MDs'.The plural form of the compound noun Medical Doctor is Medical Doctors.The plural possessive form is Medical Doctors'.
The plural form for the proper noun Susan is Susans; the plural possessive form is Susans'.
The plural of party is parties.
The plural form for the proper noun Finn is Finns.
The plural form for the proper noun Tommy is Tommys.
bnei mitvah (בני מצוה) is the proper plural form.
The plural form for the proper noun Ross is Rosses; the plural possessive form is Rosses'.
The plural form for stimulus is stimuli.