I looked up the German translation of 'proficiency' tonight and while I found 'Können' for 'proficiency' as a standalone word, 'proficiency in English' produced 'Kenntnisse in Englisch'. Can anyone explain the difference between the two words and how they might each be used?
Profiency should be translated with Kenntnisse only.
»Das Können« is the verb können (to be able to) made into a noun. It's closer to ability than profiency, though ability is often translated with Fähigkeit.
Usually, »das Können« describes a shirtsleeved form of ability.
Du bist aber schnell fertig mit deiner Arbeit! — Tja, das ist halt Können.
Well, you have your work done very quickly! — Gee, that's called a-b-i-l-i-t-y.
Someone who just can do something is also described as a Könner.
Kenntnis = knowledge
Können = skill
easy as that.
Looking at the definition in the free dictionary, I´d say proficiency is Können.
Merriam-Webster´s simple definition ("good at doing something") takes the same direction, while the full definition ("well advanced in an art, occupation, or branch of knowledge") allows both Kenntnis and Können imo. The learner´s definition ("good at doing something : skillful"), points at Können again.
This came just to my mind: proficiency sounds related to profession; and my stomach tells me that the closest translation is probably Fertigkeit or Fähigkeit ... in English: skill (again) afaik.
Können refers to ability, while kennen does to knowledge and familiarity.
Generally, proficiency would thus be translated to Können.
In a language, however, knowing and command is more or less the same - Thus German has decided to translate proficiency with Kenntnisse. We don't normally refer to a language with können other than in colloquial German.
Ich kann kein Englisch
Is a colloquial variant of
Ich beherrsche die englische Sprache nicht
Which is a pretty literal translation of I have no command of the English language