Greek is a richer and more expressive language... for him... because he's better at it.
His greek may be better than my English and so, his greek would be more expressive than my English. But, English is certainly a very expressive language. I have to say that I feel very strongly that no language can possibly be more expressive or richer. That's very subjective and generally says more about one's own ability in one laguage over the other. I find English MUCh more expressive than Spanish... becuase I dominate it. I know all of it's little nuances and how to play with words. I understand implications that most non-native speakers (even if they've been speaking the language for half their lives) cannot possibly understand.
A language is much more than words or syntax but also culture, expression, entonation, etc...
To not be able to express oneself as richly in one laguage over the other is only a sign of one's limitations in one of the languages and one's domination in the other language.
Sorry to rant. But I used to think this too. Then I realized... it was just me.
As far as the EP goes... I am sure as Matrona and others say, he knows English quite well. And although i agree with Matrona on a Practical level (let's face it, English right now just is more important in international communication... and that will change.. but right now that's just a sad fact for us English speakers (bc we have been trained not to step outside of our box).
However, that said, the EP has bishops under him that serve a more local flock. it isn't necessary for the EP to know English very well when he can speak through the corresponding bishop under him. Otherwise, he would have to learn a LOT of languages and although that would be ideal and certainly some have done so (look at the pope), time and personal talent are needed to do so.
Just my POV.
Xpy