Не стоит резать хлеб в темноте: можно порезаться.

Не стоит + infinitive is a soft recommendation: It’s not worth doing / You’d better not do.

• Не стоит резать… = “You really shouldn’t (it’s a bad idea),” often because it’s impractical or risky.
  Compared to:
• Не надо = “Don’t (please don’t)” / “No need to” (can sound more direct or like advice/command depending on context).
• Нельзя = “You must not / It’s forbidden / It’s not allowed” (a rule or strict prohibition).

In не стоит резать…, стоит is used in an impersonal construction. The implied subject is something like “it” (i.e., “it is worth…”), not “you.” That’s why it stays стоит regardless of who is being advised.

Резать (imperfective) fits general advice about an activity in general: “cutting bread (as a habit/in that situation).”
Other options change nuance:

• порезать хлеб (perfective) often means “cut (some) bread” as a completed action.
• нарезать хлеб (perfective) is common for “slice bread (into pieces)” and focuses on producing slices. In a warning/advice sentence, imperfective резать is very natural.

Because резать takes a direct object: “to cut what?” → хлеб.
For masculine inanimate nouns like хлеб, the accusative singular looks the same as the nominative: хлеб.

В темноте uses в + prepositional (locative meaning): “in (the state of) darkness.”

• Base form: темнота
• Prepositional singular: в темноте
  It describes the environment/conditions, not movement.

Not exactly.

• в темноте = “in the dark” (focuses on lack of light as a condition).
• в темной комнате = “in a dark room” (focuses on a specific place; still implies low light, but it’s more concrete).

The colon introduces an explanation/result: “Don’t do X: you might Y.”
You could also write:

• Не стоит резать хлеб в темноте — можно порезаться. (dash = very common in informal writing)
• Не стоит резать хлеб в темноте, потому что можно порезаться. (more explicit “because,” slightly heavier/longer)

Here можно is impersonal and means “it’s possible (that)… / you might…”.
So можно порезаться = “you could cut yourself / you might end up cutting yourself,” not permission.

Порезаться means “to cut oneself” (accidentally). The -ся marks that the action happens to the subject.
It’s the natural verb for accidental self-injury with something sharp (knife, glass, paper, etc.).

• порезаться (perfective) = “to cut yourself (once / as a result)”—focus on the incident/outcome.
• резаться (imperfective) can mean “to be cutting oneself (repeatedly/in general)” or “to cut oneself easily” depending on context, but it’s much less common for this warning.
  For a one-time possible accident, можно порезаться is the standard choice.

Russian often omits the subject when the meaning is general or addressed to “anyone/you” in a generic sense. Both parts are impersonal:

• Не стоит… = general advice
• можно… = general possibility
  Adding тебе/вам is possible but changes tone:
• Тебе не стоит… sounds more personal.
• Вам не стоит… sounds more formal.

Common stress/pronunciation points:

• не стои́т (stress on the second syllable: сто-и́т)
• реза́ть (ре-за́ть)
• хлеб (single syllable; final consonant is devoiced: sounds like khlep)
• в темноте́ (тем-но-те́)
• мо́жно (мо́-жно)
• пореза́ться (по-ре-за́-ться)