Hey,
They all have different focuses. Eng lang: how & why do we use language (eg why do people use slang and how is it created?)
Literature: How does the text reflect and contribute to reality? (Eg what allegories are present & why?)
English: same stuff you've been doing for years
Note: to get less subjective information about them it would be good to look at the study designs.
Imo eng lang is the most different out of the others. It doesn't have an assessed speech or assigned texts, and the 2 hour exam has short answer questions, an analytical commentary (analysis of text you see for the first time in the exam) and an essay.
(I studied this in year 12)
Literature is similar to english but you go deeper into the text, author & context. Expect to write essays, creative pieces, and deliver a speech. Literature classes can operate quite differently across schools, and I've found that people usually either love it or hate it.
(I studied this in year 11)