The imperative form of a verb is used to order someone to do something. For example, in the sentence "Go to school." the verb to go is in the imperative form.
In Turkish, the imperative has three forms, depending on the level of politeness and the number of people you are addressing.
The first form is informal and used to address a single person. This form is identical to the stem of the verb.
You will learn about the other forms in the next lesson.
As you can see above we do not necessarily need to use bir where we encounter a or an in English. However, if we do not use the word bir, the sentence can become ambiguous, as you can also see above. This is because we normally do not use the plural suffix for indefinite plural objects.
Indefinite objects are general non-specific objects, whereas definite objects are specific objects, such as for example the books, or these books. You will learn how to say read the books in Turkish in a later chapter about the accusative case suffix.