Learn Russian: По окончании работы секатор надо мыть как можно лучше. - After finishing the work, the pruning shears must be washed as well as possible.

The phrase как можно translates literally to 'how it is possible.' When you combine it with a comparative adverb or adjective, like лучше (better), it maximizes that quality. Together, they mean 'as well as possible' or 'the best you possibly can.'

Why is it по окончании and not по окончанию? Doesn't the preposition по usually take the dative case?

Usually, yes! But when по is used to mean 'after' or 'upon' an event, it requires the prepositional case. The nominative word is окончание (ending or completion), and its prepositional form is окончании. So по окончании работы specifically means 'upon completion of the work.'

In English, 'pruning shears' is plural. Why is секатор singular in Russian?

Unlike English, where tools with two blades like scissors or shears are always plural, Russian treats секатор as a standard singular masculine noun. While standard scissors (ножницы) are plural in Russian, секатор is a borrowed word that acts as a singular object.

Why do we use the imperfective verb мыть (to wash) here instead of the perfective помыть?

The imperfective is used because this is a general instruction or a habitual action. The sentence tells us what must be done every single time the work is finished, focusing on the rule itself rather than a one-time, completed result.