So Do I and Neither Do I.

1.Saying that the same is true for you

Use So do I and Neither do I to say that another person’s statement is also true for you. The verb in your response changes to match the original statement: So am I, Neither can I, and so on.

These responses mean more than “I agree”: they say that you share the same situation, experience or feeling.

2.The two response patterns

Use so after a positive statement and neither after a negative statement.

Original statement	Response pattern	Example response
Positive	So + auxiliary + subject	So do I.
Negative	Neither + auxiliary + subject	Neither do I.

An auxiliary is a helping verb such as do, have or will. We also use be and modal verbs such as can in these patterns.

The verb goes before the subject, but the response is a statement, not a question.

3.Choosing the right verb

Match the tense and the auxiliary or modal verb in the original statement. If there is more than one auxiliary, use the first one: “I’ve been working.” — “So have I.”

Verb form in the statement	Original statement	Matching response
Present simple: most verbs	“I work from home.”	“So do I.”
Past simple: most verbs	“I didn’t sleep well.”	“Neither did I.”
Present simple: be	“I’m tired.”	“So am I.”
Past simple: be	“I wasn’t ready.”	“Neither was I.”
Present continuous	“I’m waiting for the bus.”	“So am I.”
Present perfect	“I haven’t finished.”	“Neither have I.”
Will	“I’ll be there.”	“So will I.”
Can	“I can’t drive.”	“Neither can I.”
Would	“I’d like some tea.”	“So would I.”

For most present simple verbs, use do or does. For most past simple verbs, use did. Do not repeat the main verb.

4.Talking about other people

The subject does not have to be I. You can say that the statement is also true for someone else. Make the response verb agree with its own subject.

Notice the changes: do → does, is → are, and were → was. Match the original tense, but choose the verb form for the new subject.

5.Other natural responses

You can also use a normal subject–verb order with too or either.

Statement	Response with so or neither	Another response
“I’m hungry.”	“So am I.”	“I am too.”
“I don’t like crowds.”	“Neither do I.”	“I don’t either.”

Me too and Me neither are common informal responses to positive and negative statements respectively. Nor do I is another correct form of Neither do I.

If the statement is not true for you, do not use an agreement response:

• “I like coffee.” — “I don’t.”
• “I can’t drive.” — “I can.”

These short responses express a difference. Their tone can sound direct, so use a friendly voice in conversation.

6.A quick response checklist

1. Is the statement also true for the new subject? If not, do not use so or neither.
2. Is the statement positive or negative? Choose so or neither.
3. Choose the matching auxiliary, be, or modal. Use do/does/did for simple-tense main verbs other than be.
4. Put the verb before the subject, and check subject–verb agreement.

Positive: “I enjoy walking.” — “So do I.”

Negative: “I haven’t been there.” — “Neither have I.”