yes
Yes, the sentence contains an adverb "silently" and a conjunction "but".
Lawson crept silently up the stairs but couldn't still his heartbeat.
He walked silently through the forest, careful not to disturb the wildlife.
"Silently" is an adverb describing how an action is done. For example, in the sentence "She walked silently," "silently" describes how she walked.
"I need to take a moment to gather my thoughts."
The adverb form of "silence" is "silently." It describes how something is done without sound or noise.
Lawson crept silently up the stairs but couldn't still his heartbeat.
If a word ends in ly, it is an adverb. But and and are conjunctions. Not is an adverb.
'Little Town' by Cliff Richard
He walked silently through the forest, careful not to disturb the wildlife.
She silently entered her house so her dad wouldn't see the time she was arriving home.
As the modifier or description of an action, e.g.,"The thief moved silently through the garden."
The Biped stood there silently.
The gutsy soldier just silently grimaced.
No, "silent" is an adjective, not an adverb. Adjectives are used to describe or modify nouns, while adverbs are used to modify verbs, adjectives, or other adverbs.
I love to just silently sit and enjoy the abounding unspoilt nature.
The adverb form of "silence" is "silently." It describes how something is done without sound or noise.
Silently is spelled S-I-L-E-N-T-L-Y.