Prospective Marriage visa

You are a spouse if you are married to your sponsor and your marriage is legally valid.

If you were married in Canada:

• You must have a Certificate of Marriage issued by the province or territory where the marriage took place.

If you were married outside Canada:

• The marriage must be valid under the law of the country where it took place and under Canadian law.
• A marriage performed in an embassy or consulate must comply with the law of the country where it took place, not the country of nationality of the embassy or consulate.

Common-law partner
You are a common-law partner—either of opposite sex or same-sex—if you have been living with your sponsor in a conjugal relationship for at least one year. The year of living together must be a continuous 12-month period and cannot be intermittent periods that add up to one year. However, you are allowed temporary absences for short periods of time for business travel or family reasons.
You will have to provide documents that prove that you and your common-law partner have combined your affairs and have set up your household together in one home. This could include:

• joint bank accounts or credit cards;
• joint ownership of a home;
• joint residential leases;
• joint rental receipts;
• joint utilities (electricity, gas, telephone);
• joint management of household expenses;
• proof of joint purchases, especially for household items; or
• correspondence addressed to either person or both people at the same address

http://www.dfait-maeci.gc.ca/canada-europa/ukraine/
http://www.cic.gc.ca/english/index.asp