Is this correct for Simple subject and predicate?
A young boy was riding a donkey down the road. Boy was riding?
Yay! You're right again!
Does "them took" make sense to you?
Hint: Remember that subjects can never be in a prepositional phrase.
http://www.chompchomp.com/terms/prepositionalphrase.htm
It is two took?
Right! "Two" is the subject. "Took" is the verb.
Yes, "A young boy was riding a donkey down the road" is a correct sentence.
In terms of the simple subject and predicate, the simple subject is typically the main noun or pronoun that the sentence is about. In this case, the simple subject is "boy." It is the main noun that the sentence is providing information about.
The simple predicate, on the other hand, is the main verb or verb phrase that shows the action or state of the subject. In this case, the simple predicate is "was riding." It is the verb phrase that describes what the boy is doing.
So, in regards to your question, the simple subject is "boy," and the simple predicate is "was riding."