Breakdown of Ему следовало бы взвесить всё, пока не поздно.
поздно
late
ему
to him, to it
бы
would (conditional particle) / concessive particle
весь
all, the whole, everything, everyone (весь, вся, всё, все)
Questions & Answers about Ему следовало бы взвесить всё, пока не поздно.
Why use the past tense следовало with бы if he needs to weigh his options now or in the future?
Adding the conditional particle бы to the past tense form следовало softens the recommendation. While ему следует is a direct 'he should', ему следовало бы translates closer to 'he ought to' or 'it would be a good idea for him to'. Even though it uses a past tense form, the advice applies to the present or future.
Why is 'he' in the dative case (ему)?
The words следует, следовало бы, and стоит are impersonal verbs. In Russian, impersonal constructions put the logical subject (the person receiving the advice or needing to do the action) into the dative case.
Does взвесить just mean 'to weigh' physically?
It does mean to weigh a physical object on a scale, but just like in English, it is widely used metaphorically. Here it means to 'weigh the options' or 'think things through'. It is a perfective verb, focusing on the result of having thoroughly evaluated everything.
How does пока не поздно translate to 'before it is too late' when пока means 'while'?
The construction пока не translates to 'until' or 'before' a certain state arrives. The literal translation of пока не поздно is 'while it is not [yet] late', which is the standard, natural Russian way to express 'before it is too late'.