Final answer:
The sentence 'Piden por agua' is grammatically correct and means 'They ask for water.'
Step-by-step explanation:
The sentence 'Piden por agua' is grammatically correct.
The subject of the sentence is 'piden', which means 'they ask' in English. This is the third person plural form of the verb 'pedir' (to ask) in the present tense. The pronoun 'ellos' (they) is implied.
Overall, the sentence is grammatically correct in Spanish and means 'They ask for water.'
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