The plural is oceans and the plural possessive is oceans' (referring to more than one ocean).
Canada is singular. It is a country, so it is treated as a single entity.
The word "neighbours" is plural. The singular form is "neighbour."
The possessive form of the singular noun country is country's.
The plural form of the noun country is countries.
The plural possessive form is countries'.
Examples:
The country's income is derived mainly from tourism.
All of the countries' representatives were in attendance as the meeting began.
The possessive form of the plural noun countries is countries'.
Example: All of the countries' delegates had to agree to the plan.
The plural possessive form of "compass" is "compasses'".
The plural form for the noun country is countries.
The plural possessive is countries'.
Example: The success was the result of many countries' cooperation.
The Mont Alto Historical Society is located at 27 South Walnut Street, Mont Alto, Pennsylvania 17237, USA.
Some examples of words ending in "f" or "fe" that form their plural by changing to "ves" are: leaf --> leaves, calf --> calves, shelf --> shelves, loaf --> loaves, wolf --> wolves, half --> halves, and knife --> knives.
The form century's is the singular possessive form of the noun century. The plural form of the noun century is centuries. The plural possessive form is centuries'.
The plural form for the verb "needs" is "need". For example, "He needs help" becomes "They need help".
Regular plural endings in English often include adding "-s" (e.g. cats, dogs), "-es" (e.g. foxes, classes), or "-ies" (e.g. cherries, babies) to the singular form of a noun.
Singular possessive: mother's Plural possessive: mothers'
The possessive plural form of "gypsy" is "gypsies'."