嘛 (ma): particle indicating obviousness or emphasis

Don't worry, Xiao Li—he can definitely help you solve this problem.

Learning Chinese—just listen and speak more, and you'll naturally get it; there's nothing to be afraid of.

It's Sunday—of course the park is crowded; let's go another day.

He's the manager—naturally he's responsible for the decisions of the whole department.

Kids—it's normal for them to make small mistakes; just teach him patiently.