My in-laws keep correcting my 'standard' Marathi—how do I sound more natural?

I’m a heritage learner and I’ve been studying textbook Marathi, but my family in Pune keeps telling me I sound like a 'book'. Whenever I use formal structures, they switch to English immediately. Are there specific colloquialisms or Pune-style shortcuts I should learn to sound less stiff and more like a local when I'm around my Marathi-speaking family?