Learn Spanish (Latin America): Uso el embudo para no derramar nada. - I use the funnel so as not to spill anything.

You use para + infinitive (the unconjugated verb, like derramar) when the subject of both actions is the same (I use the funnel, and I am the one who won't spill). If you were using the funnel so that someone else wouldn't spill, you would use para que + subjunctive (for example, para que tú no derrames nada).

Why does no come before the infinitive derramar?

When negating an infinitive verb in Spanish, the no goes immediately before it. The structure para no + infinitive is the standard and most natural way to translate the English phrases "in order not to" or "so as not to".

Could I use tirar instead of derramar here?

Yes, tirar is often used colloquially in Latin America to mean "to spill" or "to knock over" a liquid. However, derramar is the specific, precise verb for spilling or shedding liquids, which makes perfect sense when talking about using a funnel (embudo).

Is no derramar nada considered a double negative?

Yes, and that double negative is required here. In Spanish, if a negative word like nada (anything/nothing) comes after the verb, you must have a no before the verb. So, "not to spill anything" directly becomes no derramar nada.