As nouns the difference between bystander and viewer

is that bystander is a person who, although present at some event, does not take part in it; an observer or spectator while viewer is someone that views some spectacle; an onlooker or spectator.

As a noun bystander

is a person who, although present at some event, does not take part in it; an observer or spectator.

As a verb observor is

.

As adjectives the difference between authorized and authoritative

is that authorized is explicitly allowed while authoritative is arising or originating from a figure of authority.

As a verb authorized

is past tense of authorize.

As nouns the difference between lense and spyglass

is that lense is misspelling of lens while spyglass is a small portable telescope.

Alense is likely misspelled.

Alense has no English definition.

As a noun spyglass is

a small portable telescope.

As adjectives the difference between unsettled and flustered

is that unsettled is disturbed, upset while flustered is confused, befuddled, in a state of panic by having become overwrought with confusion.

As verbs the difference between unsettled and flustered

is that unsettled is past tense of unsettle while flustered is past tense of fluster.

Unrequite is often a misspelling of unrequited.

Unrequite has no English definition.

As an adjective unrequited is

unanswered; not returned; not reciprocated; not repaid.

In grammar terms the difference between preterite and imperative

is that preterite is the preterite tense, simple past tense: the grammatical tense that determines the specific initiation or termination of an action in the past while imperative is of, or relating to the imperative mood.

As nouns the difference between lop and hew

is that lop is a flea while hew is hue; colour.

As verbs the difference between lop and hew

is that lop is to cut off as the top or extreme part of anything, especially to prune a small limb off a shrub or tree, or sometimes to behead someone while hew is to chop away at; to whittle down; to mow down.

As nouns the difference between etymology and linguistics

is that etymology is the study of the historical development of languages, particularly as manifested in individual words while linguistics is the scientific study of language.