I feel you... but I am trying to see it from the positive side albeit being a bit irritated at times. Our routine is to go over to my in-laws' place every Sat evening for dinner. My mil will without fail call up every Friday evening ard same time to (1) chope us for dinner for Sat night (2) tell us that she will go to the market sat am to buy fish n meat (for me to cook for my lo - who is their first grandchild). When they do come over, my hubby ensures he is in command, tells my mil to sit down n be a guest n not meddle around. He is firm on that. My fil never lifts his fingers to do chores so i m not worried abt him fussing ard in my place. So, make it a routine, plan to go over every Sat am or Sun am etc.. (we skip sun Pm bec we have pre monday blues)...
Abt speaking in broken English, just ask ur spouse to 'mediate' and tell his parents to talk in mandarin to ur child. if we talk, we are deemed as disrespectful n rude... tell u smtg funny, i detest baby talk with saying everything twice... like my mil fil will say sit sit, eat eat, ball ball... then the ultimate was when we were outside, they pointed to a mynah n told me daughter... "bird bird". i couldnt stop laughing n cringing if u know what i mean. So mommy u are not alone. all the best!