Parse ON in the sentence … John walks on the roof.
ON is a preposition. It is placed before the noun roof and it shows a relation between roofs and walks. It tells on what he walks.
Parse each of the Prepositions in the following sentences.
John went to Boston on the boat.
The old mill stood beside the road.
The city of Philadelphia is situated between two rivers.
He went in a carriage drawn by two horses on a line day in the morning into the city after his sister. As he rode over the roads and through the streets, he saw objects before him with which he was greatly pleased.
When the widow stood beside the grave of her husband, she thought over his many acts of kindness towards her. Now he was to rest beneath the clods of the valley, and she was to be left without a partner. The good minister told her to look for comfort in her affliction unto her heavenly Father and to think of that blissful abode above the weary world, and of that better life beyond the grave. .
Parse all the other words in the foregoing sentences.