Final answer:
To construct a sentence with both 'supposed' and 'supposed to', you could say: "Even though the instructions were supposed to be clear, John supposed they were ambiguous and asked for further clarification."
Step-by-step explanation:
The question requires constructing a sentence that uses both 'supposed' and 'supposed to' properly. It is essential to note that in standard English, subject/verb agreement is critical, which means ensuring that a singular subject is paired with a singular verb, and a plural subject with a plural verb. Mixed sentence constructions, as well as passive-voice sentences, often lead to a lack of clarity and should generally be avoided when striving for vigorous and direct writing.
A correct example sentence that includes both 'supposed' and 'supposed to' might be:
"Even though the instructions were supposed to be clear, John supposed they were ambiguous and asked for further clarification."