Key Concepts:
1. The Simple Present Tense is used to talk about general truths, habits, and routines.
2. The Present Continuous Tense is used to talk about actions happening at the moment of speaking or temporary situations.

Usage Examples:
1. I play football every Sunday. (मैं हर रविवार फुटबॉल खेलता हूँ।)
2. She always brushes her teeth before going to bed. (वह हमेशा सोने से पहले अपने दांत साफ करती है।)
3. They are watching a movie right now. (वे अभी एक फिल्म देख रहे हैं।)
4. He is studying for his exams this week. (वह इस हफ्ते अपनी परीक्षाओं के लिए पढ़ रहा है।)

Key Mistakes:
1. Using the Simple Present Tense for actions happening at the moment.
Incorrect: I play football now.
Correct: I am playing football now. (मैं अभी फुटबॉल खेल रहा हूँ।)

2. Using the Present Continuous Tense for general truths or habits.
Incorrect: She is always brushes her teeth before going to bed.
Correct: She always brushes her teeth before going to bed. (वह हमेशा सोने से पहले अपने दांत साफ करती है।)

Remember, the Simple Present Tense is used for things that happen regularly or are always true, while the Present Continuous Tense is used for actions happening right now or temporary situations. Practice using these tenses correctly to improve your English speaking and writing skills.