Choose the sentence which is grammatically incorrect:

The correct answer is Option (3) → To finish all ten chapters of History in two days seem impossible to me.

Subject-verb agreement with a to-phrase as the subject:

• The given sentence says “To finish all ten chapters ... seem”.
• A phrase with “to” used as the subject names one action, so it takes a singular verb.
• “Chapters” is only part of the phrase. It is not the subject.
• Corrected: To finish all ten chapters of History in two days seems impossible to me.

Why the Other Options are Incorrect?

Option 1: The advice of our old family doctor is always simple and practical. This sentence is correct. The subject is “the advice”. “Advice” cannot be counted, so “is” is right.

Option 2: Lots of homework has been given to us for the Diwali break. This sentence is correct. After “lots of”, the verb agrees with the noun that follows. “Homework” cannot be counted, so “has” is right.

Option 4: Half of the birthday cake was eaten before the guests arrived. This sentence is correct. After “half of”, the verb agrees with the noun that follows. “The birthday cake” is singular, so “was” is right.