Present Simple vs Present Progressive (Continuous)

Use the present continuous for actions happening now or around now, and the present simple for habits, routines and things that are generally true. Compare "The water is boiling, be careful" (happening now) with "Water boils at 100 degrees Celsius" (always true), and "What language are they speaking?" (now) with "Do you speak English?" (in general).

Both are correct, but they mean different things: the present simple is for permanent situations, the present continuous for temporary ones. "My parents live in London" means it is their home. "I'm living with some friends until I find a place of my own" means it is only for now. The same goes for work: "Sarah works in a hospital" (her job) and "Sarah is working in a café this summer" (for a short time).

Yes, the present continuous also covers actions in progress around now, even if they are not happening at the moment you speak. "Jane wants to work in France, so she's learning French" is true even while Jane is asleep. In the same way, you can say "I'm reading a great book" over lunch. For a regular habit, use the present simple: "I read every evening."

"What do you do?" asks about someone's job, and "What are you doing?" asks what they are doing right now. The first is present simple, the second present continuous. So you answer "What do you do?" with "I'm a nurse" or "I work in a hospital", and "What are you doing?" with "I'm cooking dinner." The same difference works with other questions: "Where do you work?" (your job in general) and "Where are you working this summer?" (only for now).

With always, the present continuous describes something that happens very often, and it usually shows the speaker finds it annoying: "They are always complaining." "They always complain" simply states a habit, while "They are always complaining" adds feeling. The feeling is not always negative: "She's always helping people" can be praise. For a neutral routine, use the present simple: "I always get up at seven."