Practice English for at least 20 minutes

[Zoli]

Does this command sound natural?

Practice English for at least 20 minutes.

 

[emsr2d2]

Does this command sound natural?

Practise English for at least 20 minutes.

Note that in BrE, "practise" is the verb and "practice" is the noun.

It's a grammatical sentence but, as it stands, it's just a command to do something right now. It would be more natural to add something like "every day" at the end.