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: The dog chased the cat , which ran up a tree . It waited at the top . paraphrase: The dog is chasing the cat , which is running up a tree . It is waiting at the top .

SOLUTION: Tense

PROBLEM: original sentence: The man couldn't lift his son because he was so weak . paraphrase: The woman couldn't lift her daughter because she was so weak .

SOLUTION: Gender

PROBLEM: original sentence: Fred covered his eyes with his hands , because the wind was blowing sand around . He opened them when the wind stopped . paraphrase: Fred's eyes were covered with his hands , because the wind was blowing sand around . He opened them when the wind stopped .

SOLUTION:
Voice