"hey" is an interjection; "the" is a definite article in both instances; "old" is an adjective; "man", "lady", and the two word phrase "roller coaster" are all nouns; "and" is a coordinate conjunction; and "rode" is a verb (in its past tense). Those who do not accept two word phrases as nouns would instead consider "coaster" as a noun and "roller" as another adjective.
With all wooden parts.
well you need lots of space and money. then a contractor and roller coaster parts.
Not really, but on other parts you experience weightlessness
That will depend on which part of the roller coaster you're talking about. The moving parts (the cars and the driving mechanisms etc) will be designed by a mechanical engineer. The structure of the roller coaster itself (the towers and trackway and the foundations on which it stands) will be designed by a civil engineer.
Well there are many parts of a coaster, includng the most important, the spine, the brain, the heart, the stomache, and the lungs. These components keep the coaster running smoothly!
There is none
the subject of a sentence may be what parts of speech' call?
The individual word "sentence" is a common noun. However, a sentence itself is comprised of many different parts of speech.
Parts of speech
Past is being used as a noun in that sentence.
Words are classified as parts of speech based on their function as a word. If they are classified based on their role in the sentence, they are parts of a sentence. (there is not much difference between the two, but there is a difference)
A grammatically correct sentence in English requires only two parts of speech, a subject and a verb. There are however eight parts of speech that can be used in infinite combinations to form sentences.