I have the following:
<% form_for @user do |f| -%> … <%= render :partial => “relationship_status” %> … <% end -%>
How do I pass f to the partial! 
Or can I not do that?
Just pass the form to the partial as a 'local' like this:
<%= render :partial => "relationship_status" %, :locals => {:form => f } %>
You can then refer to the form in your partial like this:
<%= form.text_field ... %>
Are you sure that you need to? If you are rendering relationship info for the user, but that relationship info relies on some other model, you might be able to:
_relationship_status.html.erb <% fields_for :relationships, relationships do |fld| %> <% fld.text_field ... %> <% end %>
and pass the user into the partial:
<%= render :partial=>'relationship_status', :locals=>{:relationships=>user.relationships} %>
The main point being that if you're rendering a partial that displays fields for a different model then you don't need to pass the form variable, but a reference to that model or collection.