Are the following sentences grammatically correct?

Question

I'm having some troubles with a more literary writing style, and I wanted to check if the following sentences are correct grammatically, and if not, what exactly is the problem and what alternatives may I find, or how can I fix it ?

Here are the sentences:

"[...] questionable and unsafe places to sleep had plunged him into a constant alertness, one that had only been reinforced when [...]"

"After what he perceived to be an uncertain amount of time [...]" the idea is that the character has lost track of time, but some time had passed nonetheless, but he is unsure of how much.

"The noise paused in front of the door" as I understand it, sounds and noises are (in the language at least) not sentient beings who can perform actions, correct ? So what would be an ideal replacement for this sentence, the idea of it being that the character can hear sounds from afar, which is getting closer before stopping in front of a door. Also, can a sound "gain proximity" ? (i.e getting closer).

"[...] he caught a glimpse of a small group of guards facing the door. Somewhere in his mind, he noted their unusual numbers, though it barely sparked any curiosity in him"

"his thoughts had been slowed down to a halt by the bland nature the days had acquired."

Any explanation or links towards articles explaining which grammar points are concerned by these mistakes would be greatly appreciated.

Answer 1

"[...] questionable and unsafe places to sleep had plunged him into a constant alertness, one that had only been reinforced when [...]"

Grammatical, but weakly written.

*EDIT - questionable = unsafe. you risk watering down the sense of danger. had plunged - why past perfect? also, hyperbole? Constant alertness - if you are not continuously [in focus], could you be said to be alert? Been reinforced - passive is OK, but why? (and, lose tempo.)

"After what he perceived to be an uncertain amount of time [...]"

Grammatical.

"The noise paused in front of the door"

Grammatically correct, semantically invalid, for the reasons you stated. Prefer "the noise stopped"

can a sound "gain proximity" ? (i.e getting closer).

Prefer "draw nearer" or, simply, "intensified," or the like

"[...] he caught a glimpse of a small group of guards facing the door. Somewhere in his mind, he noted their unusual numbers, though it barely sparked any curiosity in him"

Numbers --> Number, singular: a large (unusually large) number

Prefer switch "it" with "this" to reinforce predicate.

"his thoughts had been slowed down to a halt by the bland nature the days had acquired."

Grammatical, but weakly written.

*EDIT - 1) idiomatic and uninspired. This is no place to make suggestions, but as you have asked, why not: "Time now ran together and his thinking, not at all. Yesterday, today, tomorrow: mere words, no longer concepts, no longer tied to anything, any anchor, of sense and sensing. His Being bled through the fifth dimension listlessly..."