The correct usage of CAN and COULD in American Casual, Spoken English using "Modal Verbs", general rules to go by (never hard and fast or forever, always, aka: always exceptions but here's a really good start)
Everybody should know about some general and common good manner. So just have a look to this pic and learn good manners. You can enhance your talking and writing with these manners. If you want any grammatical help then you can take help from here.
8 important phrasal verbs of movement [infographic] Phrasals are phfun! These little nuggets have no rules and simply develop through use within the English language. Here are eight phrasal verbs based on movement.