For English language learners, retrieval practice is highly effective because it moves new vocabulary and grammar from short-term to long-term memory. Retrieval practice strengthens neural connections each time you retrieve a word, a rule, or other information. Retrieval practice is much more effective than passive strategies like rereading notes or highlighting.
There isn't a single "perfect" schedule, but a common and highly effective method for language learning is spaced retrieval practice. This is when you progressively increase the time between your retrieval attempts.
Here's a spaced retrieval practice schedule for a new set of vocabulary words or a grammar concept:
Day 1: New words or concepts are presented.
Day 2: Retrieval Practice #1
Day 4: Retrieval Practice #2
Day 8: Retrieval Practice #3
Day 16: Retrieval Practice #4
Day 32: Retrieval Practice #5
Day 64: Retrieval Practice #6
The key is that the time between sessions gets longer.