Easy English with could

Hi, guys. how are you? how is going your day? my days going not good. I am ill with some seasonal problems. today I say could be. could be is important when you can't find an action verb at that time you can use "be". like study well, the exam could be tuff this time. this business could be dangerous for you. lots of examples have. Could you give me a pen, please? Could I put my pen on the table? It could rain yesterday. It could rain today. It could rain yesterday. It could flood yesterday. It could winter today. It could sun yesterday. When i was teenagers, i could eat 60 biscuits.when I was 12 years, i could go to 50 km without rest. When i was 15 years, i could eat 14  Parata without water. I wish i could go to Switzerland. I wish, Rajib could go to America. I wish, jishan could go to cumilla. If i had got 5000tk, i could have gone to cox’s Bazar. If i had got a bike, i could have gone to Indonesia. Water is cloudy, it could rain today. Water is rainy, it could flood today. Drive slowly, you could meet with an accident. Study well, the exam could be tuff this time. if you don’t study well, you could be fail in the exam.raju could be at home.his shop could be close now.
 no more now .. have a nice day.