The following sentence has been split into segments. One of them may contain an error. Identify the segment that contains a grammatical error. If you don’t find any error, mark ‘No error’ as your answer.
No one were / present when I / entered the hall.

To identify the grammatical error in the sentence, let us analyze the subject-verb agreement step-by-step:

1. Analyze the Subject:
The subject of the sentence is the pronoun "No one". In English grammar, indefinite pronouns such as "no one", "everyone", "someone", "nobody", and "anyone" are always treated as singular nouns.

2. Analyze the Verb:
The verb used with this subject is "were", which is the plural form of the past tense verb "to be".

3. Apply Subject-Verb Agreement Rules:
A singular subject must be paired with a singular verb. Since "No one" is singular, it requires the singular past tense verb "was" instead of the plural verb "were".

4. Correct Sentence Structure:
The grammatically correct version of the sentence is: "No one was present when I entered the hall."

Therefore, the segment containing the grammatical error is "No one were".