“What did you do this weekend?” “I worked in the yard, 'mostly'.” [=I spent most of my time working in the yard]
The people at the concert were 'mostly' older people. [=most of the people were older people]
He gets around 'mostly' [='mainly, chiefly'] by car. [=he usually uses a car to get around]
(..) It's your surprise birthday again. It's half an hour earlier. She's all stressed out every year. She's inviting all my family, every year it's exactly the same deal. They're mostly coming to see if I'm still alive. Just checking... And I pretend to be surprised. Everyone's doing their best. (..)2011 The Intouchables
(..) I have a high school "Proximity Services" diploma and a bachelor's in "Social and Familial Economy" I don't... like... I mean... I have been mostly studying rather than working. What is your main motivation? Money! Mankind. I'm all about mankind. Good for you. (..)2011 The Intouchables