Simple Present vs. Present Progressive

What's the difference between the Present Simple / Present Progressive (or Continuous) and how to use them.
We use the present simple tense when we want to talk about fixed habits or routines – things that don’t change.

We use the present continuous to talk about actions which are happening at the present moment, but will soon finish.

Compare these two statements:
(present simple) I play tennis.
(present continuous/ progressive) I am playing tennis.

(present simple) ‘I play tennis’ tells us that playing tennis is something the speaker always does. It is part of a routine or habit. We can call this a permanent situation.

(present continuous/ progressive) ‘I am playing tennis’ tells us that the speaker is playing tennis right now. Soon the game will be over. We call this a temporary situation.

With the present simple we say:

I play tennis
You play tennis
We play tennis
They play tennis
He/she/ it plays tennis.

With the present continuous we say:

I am playing tennis
You are playing tennis
We are playing tennis
He/she/it is playing tennis

Frequency Adverbs we use with the Present Simple
With the present simple we use these frequency adverbs:
(Notice that the adverb comes before the main verb in the sentence.)

Always: ‘I always read before I go to bed.’
Often: ‘Her sister often comes shopping with us.’
Frequently:‘Michael frequently visits his family.’
Sometimes:‘You sometimes go to the gym, don’t you?’
Occasionally:‘It occasionally rains in summer.’
Seldom:‘They seldom ask for help.’
Rarely: ‘He rarely goes out without his backpack.’
Hardly ever:‘I hardly ever eat pizza.’
Never: ‘Japanese people never wear shoes inside.’

Time Expressions we use with the Present Continuous:
With the present continuous we use these time expressions:
(Notice that the time expression can come at the start or at the end of the sentence.)

At the moment: ‘I’m watching TV, at the moment.’
These days: ‘Paul’s living in Cardiff, these days.’
Now: ‘What are you doing, now?’
Nowadays: ‘I think you are smoking too much, nowadays.’