Writing prompt: Tom and Sam

Student essay:
Sam and Tom are good friends.They have someways the same and some difference.Sam is smarter than Tom,and Sam is also taller than Tom.But Sam is not as thin as Tom,he is heavier than Tom.So Tom runs faster than Sam.Though they get up as early as each other.But Tom is not so hard-working as Sam.Tom is not as funny as Sam too. But he is friendlier than Sam.They are both popular with their classmates.

Corrected essay:
Sam and Tom are good friends. They have some ways the same and some differences. Sam is smarter than Tom, and Sam is also taller than Tom. But Sam is not as thin as Tom. He is heavier than Tom. So Tom runs faster than Sam. Though they get up as early as each other, Tom is not so hard-working as Sam. Tom is not as funny as Sam too. But he is friendlier than Sam. They are both popular with their classmates.

Error analysis:
error_sentence: They have someways the same and some difference.
correct_sentence: They have some ways the same and some differences.
error: someways
correction: some ways
error_type: Space Error
error_severity: 1
error_description: Space Error: In the original sentence, 〈someways〉 incorrectly merges “some” and “ways”; in English, these are two separate words and should be written as 『some ways』, meaning “in some aspects”. The original sentence lacks the necessary space between words, leading to an expression error.

error_sentence: They have someways the same and some difference.
correct_sentence: They have some ways the same and some differences.
error: difference
correction: differences
error_type: Noun Number Error
error_severity: 3
error_description: Noun Number Error: According to English grammar, when “some” modifies a countable noun, if it indicates more than one, the noun must be in its plural form. In the original sentence, “difference” after 〈some〉, combined with the context, indicates multiple differences, and should use the plural form 『differences』 to maintain number agreement.

error_sentence: But Sam is not as thin as Tom,he is heavier than Tom.
correct_sentence: But Sam is not as thin as Tom. He is heavier than Tom.
error: ,he
correction: . He
error_type: Punctuation Error
error_severity: 2
error_description: ① Punctuation Error: The original sentences “Sam is not as thin as Tom” and “he is heavier than Tom” are two independent main clauses and cannot be connected merely by a comma; there is a comma splice error. 〈,he〉 should be changed to 『. He』 to correctly separate the two sentences; ② Space Error: According to English writing conventions, a space is needed between the period and the word 『He』.

error_sentence: Though they get up as early as each other. But Tom is not so hard-working as Sam.
correct_sentence: Though they get up as early as each other, Tom is not so hard-working as Sam.
error: .But
correction: ,
error_type: Word Redundancy Error
error_severity: 4
error_description: ① Punctuation Error: 〈Though〉 introduces a concessive adverbial clause; the clause and the main clause cannot be separated by a period and should be connected by a comma. In the original sentence, a period is used between 〈Though they get up as early as each other.〉 and 〈But Tom is not so hard - working as Sam.〉, which disrupts the structure of the complex sentence. 〈other.〉 should be changed to 『 other,』 to correctly connect the clause and the main clause; ② Word Redundancy Error: According to English grammar rules, both 〈Though〉 and 〈But〉 are used to express a contrasting relationship, but they cannot appear in the same sentence simultaneously. The original sentence uses both 〈Though〉 to introduce the clause and 〈But〉 to introduce the main clause, causing semantic redundancy. 〈But〉 should be deleted, retaining one of the concessive conjunctions to make the sentence correct and concise.