I noticed today that halfway through the lesson the teacher seems to have started doing something else while teaching me.
ご質問ありがとうございます。
「今日の講師は[途中](https://eikaiwa.dmm.com/uknow/questions/48134/)まで他の作業しながら教えてたように見えた」は英語で「I noticed today that halfway through the lesson the teacher seems to have started doing something else while teaching me.」と言います。
また、「途中まで」は「 halfway through」という意味です。
「〜のように見えた」の場合、「I noticed that...seems to have」になります。
ご参考になれば幸いです。
I can't be sure about this, but it appeared as though today's instructor was doing something else while he/she was teaching me, up to a certain point in our lesson.
ご質問ありがとうございます。
"I can't be sure about this,"=「断言はできない、」
"but it appeared as though today's instructor was doing something else while he/she was teaching me,"=「でも、今日の講師は、私を教えているときに、何か別のことをしているようだった」
"up to a certain point in our lesson."=「レッスンのある時点まで。」
☆「〜のように見えた」は"it appeared as though ~"と訳しました。"It seemed as though~"とも言えます。
ご参考までに。