The who clause will describe or tell more about a person.
The which clause will describe or tell more about a thing.
Tom, who couldn't carry a tune, sang to his cat.
The cat, which was his only company, was frightened.
Adverbs before verbs.
Speedily ran. Quickly ran. Drunkenly ran.
The hare was delighted because he knew it would be an easy race.
When, while, where, since, as, if, although
Adverb Clause, in middle of a sentence. The have slept while the tortoise plodded on.
Dual adverbs, verbs, or adjectives
fearfully and desperately
taunted and tormented
clever but deceitful
use "that" or omit the word and leave the clauseThe king of the beasts never imagined (that) a puny rodent could help him.
Adverbial and adjectival "teeter-totters"
Adverbial: Dual adverbs before the verb with an adverbial clause following:
The fox secretly and cruelly laughed as the foolish crow began to sing.
Adjectival: Dual adjectives before a noun with an adjective clause following:
The hare scoffed at the humble, lethargic tortoise who had challenged him.