Sentence Correction

The sentence provided is: "Each of the students have submitted their assignments on time." The objective is to identify the part containing a grammatical error. Let's analyze the sentence:

1. Each of the students: Here, 'Each' is a singular pronoun. When it is followed by a prepositional phrase like 'of the students', the verb should agree with the singular pronoun 'Each'.

2. have submitted: The error lies here. The verb 'have' is plural, but it should be singular to match the singular subject 'Each'. Therefore, it should be 'has submitted'.

3. their assignments: This phrase is correct because 'their' refers to 'students', which is plural in the context of assignment ownership.

4. on time: This is a correctly used adverbial phrase modifying when the action of submitting occurred.

The correct form of the sentence should be: "Each of the students has submitted their assignments on time."

The sentence under review is: "She gave a beautiful speech, which everyone enjoyed it." The part of the sentence needing improvement is underlined as: which everyone enjoyed it. We aim to optimize this sentence by selecting the best alternative from the provided options.

To resolve this, let's analyze the grammatical issue. The sentence uses a nonrestrictive relative clause, yet the inclusion of "it" creates a redundancy issue because the relative pronoun "which" already refers to speech, making "it" unnecessary.

We need an alternative that effectively links the main clause and the relative clause without redundancy. Out of the available options:

1. which everyone enjoyed
2. that everyone enjoyed
3. whom everyone enjoyed
4. who everyone enjoyed

Explanation of the options:

• which everyone enjoyed: The pronoun "which" is correct but should not be followed by "it." Since it's a relative pronoun, "it" is unnecessary. However, restrictive and nonrestrictive clauses rules suggest "that" for essential information.
• that everyone enjoyed: Corrects both the pronoun issue and redundancy by ensuring the clause directly modifies "speech" without additional pronouns.
• whom everyone enjoyed: "Whom" is used for people, not inanimate objects like "speech."
• who everyone enjoyed: "Who" is also used with people, not objects.

Therefore, the most suitable choice based on grammatical correctness is: that everyone enjoyed. The improved sentence is: She gave a beautiful speech, that everyone enjoyed.