Study Mode

hi I just join Skritter today and i cant seem to find whats the difference between Study Mode: Add and Review? it doesnt seem to do much in the “study”

What am i suppose to do when “what’s the definition” comes in from “Study” say aloud? LOL

Lastly I edited the mnemonics from my lists but doesnt really reflect in “Study” unless its shows the phrase itself. If it shows singular characters, shared mnemonics are used

TIA

Study: reviews old words and adds new words
Review: no new words