Here's what the guide for sponsoring a spouse/common-law partner/children who lives outside Canada says about the Additional Family Information: http://www.cic.gc.ca/english/information/applications/guides/3999Etoc.asp#3999E4
As you can see, it does not state anywhere that "you don't include your spouse/common-law partner if they are your Canadian sponsor". This form is to capture all your family members (spouse/common-law partner, children, brothers & sisters, parents).
So if you are married/common-law, your spouse/common-law partner's name(who is your Canadian sponsor) goes in line 2. Otherwise, write N/A. We have a lawyer representing us and has not told us this is incorrect.
When it comes to the "Dependents" section of form IMM 0008, it says right above the question that, "
include your spouse/common-law partner and children who are NOT already Canadian citizens or permanent residents". So your sponsor and any children who are citizens/PRs should not be listed here.
Additional Family Information (IMM 5406)
Who needs to fill out this application form?
This form must be completed by:
•You, as the principal applicant,
•Your spouse or common-law partner (whether accompanying you to Canada or not), and
•Your dependent children aged 18 or over (whether accompanying you to Canada or not).
SECTION A
Write the personal details for:
•yourself,
•your spouse or common-law partner, (if applicable)
•your mother, and
•your father.
SECTION B
Write the personal details for your children. It is very important that you list all of your children (even if they are already permanent residents or citizens of Canada). This includes:
•married children,
•adopted children,
•children of your spouse(step-children) or common-law partner,
•any of your children who have been adopted by others,
•any of your children who are in the custody of an ex-spouse, former common-law partner or other guardian.
You must answer all questions. If any sections do not apply to you, answer “N/A”.
SECTION C
Write personal details about your:
•brother(s),
•sister(s),
•half-brother(s) and half-sister(s),
•step-brother(s) and step-sister(s).
SECTION D
After carefully reading the statements contained in this section, sign and date the declaration.
Graihn said:
Maybe should tell you this now also, as you will stumble upon the same thing under the form "Additional Family Information".
Do NOT list your spouse or common-law partner here if your spouse/common-law partner is your Canadian sponsor, but you will need to list all of your family members, EVEN if they aren't accompanying you to Canada.
Hope that helps, and this:
http://www.cic.gc.ca/english/information/applications/guides/3999Etoc.asp#3999E4
include the