Permanent Residents and naturalized Canadians who have come to Canada alone will want to sponsor their dependents and spouses after they have their permanent residency if they did not at the time they applied for PR. This is called the ”Family Sponsorship” or the “Spousal Sponsorship”. These programs allows for PRs and Canadians to bring in their families and allows them to also get permanent residency.
Many Canadians who have lived in Canada may decide they want to return to their home country and get married. After their nuptials, they can also sponsor their new partners and bring them to Canada. We are one of the many countries that recognize and allow same sex relationships so spouses can be allowed to sponsor same sex partners.
Common law relations for the purpose of immigration are recognized if you and your partner have lived together for a period of one or more years. This person is considered a spouse even though you have not formalized the relationship. In some countries divorce is not allowed and couples have separated and started another relationship so in these cases, common law couples are very common.
For those of you who live in countries that allow for one or more wives, in Canada this is not recognized and illegal. It is considered polygamous and not allowed in Canada. Therefore you will have to select only one of your wives to bring and divorce or leave the others.