I've studied English for about a year now, but I feel I've made little progress.
I started studying English a year ago, but I've made less progress than I expected.
It has been a year since I started learning English, but I haven't made as much progress as I'd hoped.
「伸び悩む」は英語で「to make little progress」、「to grow less than expected」、「to make less progress than expected」といいます。
「Expected」は「期待していた」という意味です。
I've studied English for about a year now, but I feel I've made little progress.
１年ぐらい英語を勉強していますが、伸び悩んでいると感じます。
I started studying English a year ago, but I've made less progress than I expected.
１年前に英語の勉強を始めたが、伸び悩んでいる。
It has been a year since I started learning English, but I haven't made as much progress as I'd hoped.
英語の勉強を始めて１年が過ぎたが、伸び悩んでいる。
It's been over one year since I began taking English lessons, but I'm not sure if I'm getting any better.
この場合、次のような言い方ができますよ。
ーIt's been over one year since I began taking English lessons, but I'm not sure if I'm getting any better.
「英語のレッスンを受けるようになって1年以上経つけど、少しでも上達しているのかわからない」
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