Final answer:
Combine the two sentences 'I know the boy' and 'His bicycle was stolen' into one by using 'whose' as the relative pronoun to indicate possession: 'I know the boy whose bicycle was stolen.'
Step-by-step explanation:
To combine the two sentences using a relative clause, we take into account the given instructions on subject-verb agreement and the appropriate use of relative pronouns. Noting that 'His bicycle was stolen' is the clause that provides additional information about 'the boy,' we can use the relative pronoun 'whose' to connect the two sentences, since it denotes possession. Thus, we arrive at the combined sentence: 'I know the boy whose bicycle was stolen.'
It's important to use relative clauses effectively to provide clarity and conciseness in writing. In the case of the provided sentences, we are taking the second sentence which has a possessive context (indicated by 'His') and turning it into a descriptive clause that defines 'the boy' mentioned in the first sentence.