What I wanted to point to are a few of his writings and jottings which would seem to show his efforts to acquire English, and what specifically he found difficult, and what he was comfortable with.
So here is a couple pages from one of his notebooks:
As you can see, what he was doing was writing down English words with their transliteration and definition in Yiddish. There seems to be no pattern as to which words he chose; "devoid" "gust" "inertia" "vary" "haunt" and so on. My guess is that these were words that he came across in speech or reading and he wanted to remember them, or they gave him trouble or something. He probably wrote them as he came across them.
Next, is part of the text of a "sermonette" for Chanukah, for children. What is fascinating about this one is that it is entirely in English - written entirely in Yiddish/Hebrew letters. Evidently reading English was difficult, or still difficult, for him, although my guess is that he understood it and spoke it without too much difficulty. One wonders how many in his congregation realized that he was doing what we see below.
I haven't tried to read it yet, but you can see it begins with a Bible quote:
"רימעמבער דהי דייז אוו אלד".סשו מאזעס ספאק טו היז פיפל דזשאסט ביפאר היז דעטה
"Remember the days of old"So Moses spoke to his people just before his death.
I should point out that much later we see whole letters written in English, so evidently he worked out whatever issues he had acquiring it. Without a doubt this collection is a treasure trove.