"Neither do I / So do I"

✅ "So do I" vs "Neither do I"

1. 🔹 "So do I" — Used to agree with a positive statement.

It means: "I also…" or "Me too" when someone says something positive.

🔸 Structure: So + auxiliary verb + subject

✅ Examples:

• "I like coffee." → "So do I." (= I like coffee too.)

• "She's tired." → "So am I."

• "They have a dog." → "So do we."

• "I will go to the party." → "So will I."

2. 🔹 "Neither do I" — Used to agree with a negative statement.

It means: "I don't either" or "Me neither."

🔸 Structure: Neither + auxiliary verb + subject

✅ Examples:

• "I don't like coffee." → "Neither do I." (= I don't like it either.)

• "He isn't hungry." → "Neither am I."

• "She hasn't finished yet." → "Neither have I."

• "We can't swim." → "Neither can I."

💡 Remember:

The auxiliary verb (do, be, have, will, can, etc.) must match the verb tense and form in the original sentence.

⚠️ Common Mistake:

Don't mix the two:

• ❌ "I don't like coffee." → "So do I." → (Wrong!)

• ✅ "I don't like coffee." → "Neither do I."