It can be difficult to choose when to use the present simple vs. the present continuous tense in English. Both, of course, talk about the present. But they are used in different situations.

First, we use the present simple to talk about permanent or long-term situations in our lives, such as our usual job, or where we live. We don't feel these situations will change very soon. On the other hand, we use the present continuous to talk about temporary situations, such as when we are on holiday, or doing a job just for a few weeks or months. We know that these situations will end soon.

For example:

I work as a teacher (present simple)
I live in Mumbai (present simple)
He studies Engineering (present simple)

vs.

I am working in a bar for the summer (present continuous)
I am living in Madrid for a few months (present continuous)
She is studying French this term (present continuous)

Second, we use the present continuous to talk about a temporary action which is happening now. It's often when we tell someone what we are doing at the moment we are speaking. For example, you are reading this article now. This is in contrast to the present simple, which we use to talk about what usually happens, or what we usually do. This describes our habits or daily routine.

For example:

I eat toast for breakfast every day (present simple)
I take a shower every morning (present simple)
He often goes to the cinema (present simple)

vs.

I am eating toast now (present continuous)
I'm taking a shower at the moment (present continuous)
He's going to the cinema now (present continuous)

Third, we use the present simple and the present continuous to talk about the future. We use the present simple to talk about future timetables (for trains or planes for example, or for classes or the cinema or theatre). On the other hand, we use the present continuous to describe definite future arrangements. A definite arrangement is when we are 90% sure it will happen. If I say 'I'm going to the cinema tonight', then probably I have already booked the tickets, or at least decided on a film, checked the time it starts, and called the friend I am going with.

When we use the present tenses to talk about the future, we generally put in a future time word to help make the sentence clearer (like 'tomorrow' 'at 3pm today' or 'next week')

For example:

The train leaves at 8pm tomorrow (present simple)
The film starts very late (present simple)
My Chinese class finishes at 3pm (present simple)

vs.

I'm meeting my friends later (present continuous)
She's working tomorrow (present continuous)
What are you doing tonight? (present continuous)

For more information about the present simple and present continuous and the other verb tenses, including videos and free interactive exercises, see http://www.perfect-english-grammar.com