The term "sideways" is one word, and it can be an adverb, when it modifies a verb to tell in what direction an action is made. It would be considered an adjective when used before a noun, e.g. sideways motion.
Yes, it means in a horizontal, side-to-side or "lengthwise" orientation, and can be the opposite of "vertically" (up-and-down, top-to-bottom).
Sunny is an adjective. We say: A sunny day. A sunny disposition. The sunny side of the street. The adverb 'sunnily' has rare but specific uses.
The adverb form of the adjective 'tragic' is tragically.
pointy
No, neither word is being used as an adverb. Position is a noun and upright is an adjective describing the position desired.
the word" comfortable " can be used both ways as an adverb or adjective.
The adverb in your sentence is 'thereafter'.
ADVERB:: Across a ship from side to side.
An adverb is a descriptive word that modifies a verb. 'Other side' does not modify a verb (eg the sentence "Dave other side glanced at Karen, who melted" does not make sense, because 'other side' isn't an adverb), and therefore is not an adverb. In a sentence that uses 'other side': "Dave met Karen at the other side of the park," 'other' is modifying 'side,' a noun, and 'side' is simply a noun, as it is a place, not a description of a verb. (Other is an adjective.)
Yes, it is almost always an adverb, but it can be an adjective (far side, far place).
its ways the side
The adverb is carefully because it describes how you crossed the street.Compound adverb
The word ways is normally a plural noun. Colloquially it can be a noun or adjective meaning a considerable distance (a ways).
No. Way is a noun. However, the slang use of "way" to mean "very" (e.g. way cool) would be an adverb.
Yes, it means in a horizontal, side-to-side or "lengthwise" orientation, and can be the opposite of "vertically" (up-and-down, top-to-bottom).
'Yet' is an adverb. The contraction haven't contains the adverb "not." They both modify the verb "heard."
Sunny is an adjective. We say: A sunny day. A sunny disposition. The sunny side of the street. The adverb 'sunnily' has rare but specific uses.