Final answer:
The sentence 'Kezia invited Lil and Else into the courtyard' is in the active voice because the subject, Kezia, is performing the action of inviting. For a sentence to be classified as passive, it typically has a form of the verb 'to be' with a past participle and can include the preposition 'by'.
Step-by-step explanation:
The sentence 'Kezia invited Lil and Else into the courtyard' is an example of a sentence written in the active voice. In active voice, the subject of the sentence performs the action of the verb. In this case, Kezia is the subject who is doing the action, which is inviting Lil and Else.
To identify whether a sentence is in the active or passive voice, look for the subject performing the action (active) or receiving the action (passive). A hallmark of the passive voice is often the presence of a form of the verb 'to be' (am, is, are, was, were) along with a past participle, and sometimes the preposition 'by'.
Here are the sentences from active voice to passive voice Note that sometimes passive voice is used when the object being acted upon is more important or when the doer of the action is unknown.