Don’t waste your time or money; it will end in tears.
I had been married to my Canadian wife for 21 years before I applied for Permanent Residency (Landed Immigrant) in Canada. We lived together in Europe for 14 years before deciding to emigrate to Canada. Actually, I wanted to go to New Zealand, but the way things work in my house is that my wife always gets her way on big decisions such as this. Canada it was!
I had owned a house in Canada for 7 years at that point, as well as 3 cars. We have 2 Canadian born children, and one dual-citizen child (British/Canadian). We also had 1 Canadian foster child. I had been an active member of the Royal Canadian Legion, Chamber of Commerce as well as various charitable organisations. I even managed to be awarded a civic medal for outstanding contributions to Canadian Society.
Immigration Agents came to my house to interview my wife and I. The process took about 2 hours. The purpose of the visit was to establish that my marriage to a Canadian citizen was not for the purpose of immigration.
It was a surreal experience. To begin, they interviewed us as a couple. The questions that they asked were fairly general in nature, and were no doubt designed to allow the Agents to gauge our mannerisms and reactions to a set of benign questions. These were the kind of questions that anyone could answer together with a partner if they had done a little rehearsal.
Next, we were interviewed individually. Now they have got you! I will not give you the specific questions that they ask, but I warn you that they are extremely personal. They ask for intricate details of events that you and your spouse have likely forgotten. Dates, times, places, motives, outcomes, photographic evidence etc., etc..
The answers you give are cross-referenced with the answers your spouse gives. There are curve balls thrown in just to keep you on your toes. You will need to be an A-list Hollywood actor to bluff your way through that. Good luck!
I did eventually get Permanent Resident status in Canada.