Grammar 1a

We use the Present Simple: for permanent situations: I live in a flat. She works for an insurance company. 

For repeated actions or habits: I use my mobile phone every day.

For general truths: The sun rises in the East. Water boils at 100 degrees. 

To tell stories, or summarise the plot of a film or book: Our hero goes off to search for the treasure, which he eventually finds after many adventures.

We use the Present Continuous: for temporary situations existing for a period at the present time: I'm staying with a friend at the moment. She's working very hard nowadays. 

For situations which are changing during the present time: The weather's getting hotter and hotter.

For actions, or repeated actions or habits, occurring at the moment of speaking: I am using John's mobile phone because I left mine at home. You're eating too fast. 

To express annoying habits with words like always: You're always borrowing money! 

When we use always with the Present Simple, it usually means 'every time': I always complain if the service is bad in restaurants. When we use always with the Present Continuous, it means 'all the time' or 'too/very often': You're always complaining that waiters are rude. We cannot use never ... again with the Present Simple.

Incorrect - I never speak to you again.

Correct - I'm never speaking to you again.

We do not usually use certain verbs in the Present Continuous, e.g.: 

appearance: appear, resemble, seem composition: consist of, contain, have connection: come from, concern, cost, fit, suit existence: be, exist knowledge: forget, know, realise, understand likes and dislikes: dislike, hate, like, Love, prefer needs and wants: need, want, wish opinion: believe, doubt, imagine, suppose, think possession: belong to, have, own, owe, possess senses: feel, hear, notice, see, smell, sound, taste 

I feel sick. or: I am feeling sick.

My feet ache. or: My feet are aching.

My leg hurts. or: My leg's hurting.