TASK DEFINITION: You will be given two sentences. One of them is created by paraphrasing the original one, with changes on an aspect, or using synonyms. Your task is to decide what is the difference between two sentences. Types of change are explained below:
 Tense: The verbs in the sentence are changed in tense.
Number: Plural nouns, verbs and pronouns are changed into single ones or the other way around.
Voice: If the verbs are in active voice, they're changed to passive or the other way around.
Adverb: The paraphrase has one adverb or more than the original sentence.
Gender: The paraphrase differs from the original sentence in the gender of the names and pronouns.
Synonym: Some words or phrases of the original sentence are replaced with synonym words or phrases. Changes in the names of people are also considered a synonym change. Classify your answers into Tense, Number, Voice, Adverb, Gender, and Synonym.
PROBLEM: original sentence: Dan had to stop Bill from toying with the injured bird . He is very compassionate . paraphrase: Dan is having to stop Bill from toying with the injured bird . He is very compassionate .

SOLUTION: Tense

PROBLEM: original sentence: The fish ate the worm . It was tasty . paraphrase: The worm was eaten by the fish . It was tasty .

SOLUTION: Voice

PROBLEM: original sentence: Anna did a lot worse than her good friend Lucy on the test because she had studied so hard . paraphrase: Anna and Lisa did a lot worse than their good friends Lucy and Paula on the test because they had studied so hard .

SOLUTION:
Number