“Also”, “too”, and “either” have the same meaning, but they are used in different ways.
They are all used to show how things or people are the same.
1. Always use “too” at the end of a positive sentence.
She likes hip-hop. I like hip-hop too.
Mark is tall. Bill is tall, too.
Gary has two sisters. Ben has two sisters, too.
2. We can use “also” with positive sentences, but we put “also” in a different place.
Use “also” after a “be verb” if there is one in the sentence.
Tina is tired. I am also tired.
Josh is smart. His brother is also smart.
Greg was sick yesterday. Mary was also sick yesterday.
Mary is sleeping. Bill is also sleeping.
Use “also” before an action verb.
He likes pizza. I also like pizza.
She lives in the city. He also lives in the city.
Greg works here. Vicky also works here.
Use “also” after modals and before action verbs.
She will go. I will also go.
They should come. You should also come.
It might rain today. It might also rain tomorrow.
3. We can use “either” for negative sentences. A negative sentence is a sentence that has the word “not”.
Always use “either” at the end of the sentence when it used this way.
She isn’t tall. Her brother isn’t tall either.
Mary doesn’t work here. Tim doesn’t work here either.
Peter wasn’t happy yesterday. Ben wasn’t happy either.
Remember that there is another way that we can use “either”. We also use “either” to give choices or alternatives.
We can either go to the beach or go to the mountain.
We can eat either fish or chicken.
4. We do not use “also” with short answers. In these cases, we use “too” or “either”. Use “too” for positive sentences and “either” for negative sentences.
A) I hate this.
B) Me too.
A) I have a cat.
B) Me too.
A) I haven’t seen that movie.
B) Me either.
A) Sally hasn’t come to class in a long time.
B) Tim either.
5. When we are writing, we can use a comma before “too” or “either”, but we do not need to do this. It is the writer’s choice.
All of my friends have a puppy. I want a puppy too.
All of my friends have a girlfriend. I want a girlfriend, too.
Summary
“Too” and “also” are used only with affirmative sentences. These are sentences that do not have the word “not”.
Put “too” at the end of a sentence.
Mary likes it. I like it too.
Bill is fast. Mark is fast too.
Put “also” after “be verbs”. Put “also” before action verbs. Put “also” between the modal and action verb if there is a modal in the sentence.
She is tall. He is also tall.
My brother exercises here. Mark also exercises here.
I will go. She will also go.
“Either” is used with negative sentences. These are sentences that have the word “not”. Put it at the end of a sentence just like the word “too”.
I don’t like it. She doesn’t like it either.
Ben didn’t come. Mary didn’t come either.
We can use “too” and “either” with short responses, but we do not use “also” in this way.
A) I have a car.
B) Me too. / Me also.
A) Mary didn’t come to the meeting.
B) Tim either.