Hola Tara

The use of the present indicative as shown in this lesson is very colloquial and it is used with people you know very well, e.g. your own children. It could be used with other adults but in a very informal atmosphere, maybe when you ask (more telling than asking really) your husband what he has to do, or the other way round : ))

Equally you could use the imperative (present subjunctive for negative commands). This is also informal but the use of the present indicative is, I would say, an extra level of informality. It is a very direct order.

Saludos

Inma