Don't worry about your active vocabulary
Many advanced English learners have a large "passive vocabulary", but they worry about the size of their "active vocabulary". They can understand many difficult English words when reading or listening, but they don't use most of them when speaking or writing in English. They feel this is a problem. They would like to use all the difficult words that they know.
If you are a learner who worries about his active vocabulary, this article may convince you to stop worrying.
People understand many more words than they use in their own conversations. One's passive vocabulary is much larger than one's active vocabulary. The total number of words actively used in one's whole life is much smaller than the total number of words understood in one's whole life.
This statement has nothing to do with foreign languages. It is about how people use their native language.