Learn Spanish (Spain): No, no vi nada allí.

In the simple past tense (Pretérito Indefinido), the "I" form usually gets an accent mark, like in comí or escribí. However, vi (I saw) and di (I gave) are exceptions. Because they are short, one-syllable words, Spanish spelling rules dictate that they do not get a written accent.

Why use a double negative (no and nada)? Doesn't that mean "I didn't see nothing"?

In Spanish, double negatives are grammatically correct and very common. When a negative word like nada (nothing/anything) comes after the verb, you are required to put a no before the verb. It translates naturally to "I didn't see anything" or "I saw nothing" in English.

Do I always have to use no with nada?

Not always. If you put the negative word before the verb, you drop the no. You could technically say Nada vi allí, and it would mean the same thing. However, putting no before the verb and nada after it is the most natural and common way to say this in everyday Spanish.

What is the difference between allí and ahí?

Both words translate to "there", but they describe different distances. Ahí usually means "there" (a middle distance, often closer to the person you are talking to), while allí means "over there" (further away from both you and the listener).