The vocabulary you have is made up of different items: some words you simply recognise when you’re reading or listening, while others you can actively use when speaking or writing yourself. You are the one who knows best how well you need to know any particular word. You can widen your active vocabulary range both by gaining confidence with your passive word base, and by noticing, and being selective with, new words that you come across You should try to use new words when offered the possibility. If you lack real-life opportunities, memory strategies can help you learn the words.