A few months ago I was on here looking for advice for readings, etc., as my now-DH and I decided to write our own ceremony basing it off of a template from our officiant. DH and I are originally from different countries (he is from Italy, I am from the US - and we live together in Spain). That being said, we had about 50 of our 170 guests who spoke little to no English attending our New Jersey ceremony.
We ended up doing the entire ceremony in English with the exception of 2 readings (1 in English - an except from Captain Morellis Mandolin and 1 in Italian - an except from the Little Prince) and we decided to say our vows in both English and Italian (as we speak both languages). That way, both sides of the family could appreciate the promises that we were making toward each other during our ceremony. It was so beautiful and we were surprised with how many compliments we got regarding how heartfelt and intimate it was to hear us repeat the vows in both languages.
I just wanted to share in case it might help someone else in the same situation. I know when we first started to think about the ceremony it was one of the more complex parts for us regarding planning, especially because we wanted to incorporate both languages.