Learn English – on/in/at the beginning stage of something

in-on-atprepositions

Please help me figure out which preposition is correct and give me a reason.

In China, students always use the book to learn alphabets in/at/on the beginning stage of learning English.

Best Answer

"In" or "at" are both acceptable to specify a stage or point in time. "On" is less used for that purposes, and tends to be more informal. Someone might say "We're on learning the alphabet in Chinese class", but it would be less likely to be written in a more formal sentence, like the one you've given as an example.

Incidentally, alphabet is singular when you are talking about only one set of letters (the "English alphabet"; but "the Greek and Tamil alphabets").