Learn Spanish (Latin America): No hay nada para la cena, hornea el pollo. - There is nothing for dinner, bake the chicken.

You are exactly right! For regular verbs like hornear (to bake), the affirmative tú (informal you) command is spelled exactly the same as the present tense él/ella/usted form. We can tell from the context of the sentence that the speaker is giving an instruction.

No hay nada literally translates to 'There is not nothing'. Isn't a double negative incorrect?

In English it is, but in Spanish, double negatives are required grammar! When a negative word like nada (nothing) comes after the verb, you must put no before the verb. It translates naturally to 'There isn't anything' or 'There is nothing'.

Why do we use para instead of por for 'for dinner'?

We use para here because it indicates purpose or destination. The chicken is intended or destined for this specific meal.

Why is it para la cena instead of just para cena?

Spanish generally requires you to include the definite article (el, la, los, las) when talking about meals like la cena (dinner) or el desayuno (breakfast) as an event, even though we drop the word 'the' in English.