"Too" means also in affirmative sentences; "either" means also in negative sentences.
Adverb. Means "also" or "as well" in affirmative or positive contexts. Usually goes at the end of the sentence. In Spanish: "tambien."
I love pizza, and my sister loves it too.
Me encanta la pizza, y a mi hermana tambien.
She speaks French, and she speaks Italian too.
Ella habla frances, y tambien habla italiano.
I am tired. Me too!
Estoy cansado. Yo tambien.
Adverb. Means "also" in negative contexts — that is, when the sentence already contains a negation (not, never, etc.). Goes at the end of the sentence. In Spanish: "tampoco."
He does not like coffee, and I do not either.
A el no le gusta el cafe, y a mi tampoco.
She has never been to Japan, and her husband has not either.
Ella nunca ha ido a Japon, y su esposo tampoco.
I cannot swim. I cannot either.
Yo no se nadar. Yo tampoco.
Common mistake
Very common error: "I don't like spicy food." — "Me too!" Wrong. In a negative sentence, "me too" does not work. Correct: "Me neither!" or "I don't either." The reverse: "I love the beach." — "Me either!" Wrong in an affirmative sentence. Correct: "Me too!" The rule is clear: affirmative = too, negative = either.
Trick to remember it
Too = also (positive sentence). Either = also (negative sentence). Does the sentence have "not," "never," "neither," or another negative? = either. Is the sentence positive? = too. Trick: look for the word "not" or any negative. If you find one, use "either." If there is no negative, use "too." Spanish clue: if you would say "tambien" = too. If you would say "tampoco" = either.
Quick rule
Affirmative sentence + also = too. Negative sentence + also (tampoco) = either.
Did you know?
"Me neither" is a very common alternative for responding to a negative sentence: "I don't eat meat." — "Me neither." Equivalent to "I don't either." Both are correct. And "so do I" is the emphatic form of "me too": "She loves traveling." — "So do I." Likewise, "neither do I" is the emphatic form of "me neither": "She doesn't smoke." — "Neither do I." These forms invert subject and auxiliary.
Exercise 1 · Pick the right one
"I have never tried sushi." "I have not _____. Let us try it tonight."
Exercise 2 · Pick the right one
"I really enjoyed that movie." "I did _____! We should watch the sequel."
Exercise 3 · Form the word
Affirmative sentence + also = too. Negative sentence + also (tampoco) = either.
Very common error: "I don't like spicy food." — "Me too!" Wrong. In a negative sentence, "me too" does not work. Correct: "Me neither!" or "I don't either." The reverse: "I love the beach." — "Me either!" Wrong in an affirmative sentence. Correct: "Me too!" The rule is clear: affirmative = too, negative = either.
Too = also (positive sentence). Either = also (negative sentence). Does the sentence have "not," "never," "neither," or another negative? = either. Is the sentence positive? = too. Trick: look for the word "not" or any negative. If you find one, use "either." If there is no negative, use "too." Spanish clue: if you would say "tambien" = too. If you would say "tampoco" = either.
Bryan López
Founder of SpeakUP Academy