Final answer:
The sentence 'You should park the car under a shady tree' in passive voice is 'The car should be parked under the shady tree.' Passive voice sentences typically include a form of 'be' and the past participle of the verb, sometimes with 'by' indicating the actor.
Step-by-step explanation:
The sentence "You should park the car under a shady tree" in passive voice would be "The car should be parked under the shady tree." This sentence is in the passive voice because it follows the structure of a modal verb (should), followed by 'be', and the past participle of the verb (parked).
To recognize the passive voice, a sentence usually includes a form of the verb 'to be' with the past participle of the main verb and can include the preposition 'by', although it can be omitted if the doer of the action is unknown or unimportant. For example, "That his house was no place for a dance party was argued by Jose" can be changed to active voice as "Jose argued that his house was no place for a dance party", shifting the focus from the subject being acted upon to the doer of the action.