A word being remembered in vocabulary learning is a bit like a person - we know a great deal of words and we know many people. But how many people are there in our lives that we know so little about?
Words that are used in several different situations within your language learning, are just like people we know well - like friends or close associates.
You cannot meet a person just the once and consider him a true friend. Equally, one cannot learn a word in Spanish and claim to know how it really fits in to the everyday language.
Quantity over quality is important in the learning of a new language. The reason is clear: you may know exactly how to say something like, "Hello, how are you?" in the target language but when you are unable to understand a single word of the response you receive back, it kind of makes it all pointless.
We know we have to learn lots of words and grow a large vocabulary learning bank. This way we can find the words to respond to such basic questions.
Imagine if a Spanish person asks you a question, one which you understood and could even repeat back. You can become stuck, at this point, with no way forward in continuing the conversation. All because your vocabulary learning bank is so low.
There are ways of accumulating a large vocabulary in your target language. You may struggle with the grammar when responding but at least you have the words to hand. It is now just a case of getting the words in the right order and getting some grammar rules cleaned up, and you are well on the way to a conversation.
Language learners of all levels have to continue learning a vocabulary. Even the fluent language speakers. Grammar may be the structure of any language but vocabulary is the heartbeat of linguistics.
We all learn languages in different ways. Some have to write down the word, others have to associate with something, or else it will dissipate from the memory. Discover what your best way of learning is and stick to that.
Sticky notes are good for remembering words. Place them around a workstation and allow your brain to subconsciously catch the eye. These can be changed at regular intervals as you learn and digest the old words. The, after a few days, one can start with another set of sticky notes with a fresh 10 or 15 new words.
Source: Steve. "Vocabulary Learning - Quantity Over Quality - The Linguist on Language." The Linguist, 17 Sept. 2017, blog.thelinguist.com/quantity-over-quality-in-vocabulary-learning.