A. We use the Present Simple:
a. to talk about something happening regularly in the present. (e.g. The children come home from school at about four.)
b. to talk about something happening continually in the present. (e.g. They live next door to us.)
c. to talk about things which are generally true. (e.g. Water boils at 100 degrees Celsius.)
d. to talk about events which is on a schedule or timetable (e.g. The train leaves for London at 9pm tonight.)
A1. We use the Present Continuous:
a. to show that something in the present is temporary. (e.g. We are living in a rented flat at present.)
b. for something happening regularly in the present before and after a given time. (e.g. I’m usually getting ready for work at eight o’clock.)
c. for something happening before and after the moment of speaking. (e.g. I can’t hear you. I’m listening to my iPod.)
A2. We use Modal Verbs to talk about the present when we are not sure of something. (e.g. I don’t know where Henry is. He might be playing tennis.)
Idiom 365
Cast Iron Stomach: be able to eat or drink anything without any problems
Example: He thought John must have a cast iron stomach when he saw him eating the spicy Korean food.