Meaning: The farmer always made sure the pig pen was clean.
Choice of Words: A "farmer" is a person who works on a farm. "Kept" means to maintain something in a particular state or condition. A "sty" is a pen or enclosure where pigs are kept. "Clean" means free from dirt or mess. "Always" means at all times. So, "Farmer kept the sty clean always" means that the farmer made sure the pig pen was clean at all times.