Much like how Grace Hopper invented the computer code COBOL, we can all be inventors of language, whether it's through using a new form of emoji, a gesture in sign language, or a new word in spoken language. This innovative process occurs when our existing vocabulary leaves gaps in what we wish to express, most likely when we are faced with ideas, concepts, and situations that are not clearly defined in our minds. Oftentimes, we then borrow from other languages, make up completely new words, or adapt already existing ones to capture what we wish to express.
For instance, in the English language, the most common method of creating a new word is by adding a prefix or a suffix to an existing word. Such is the case with words like 'unbelievable,' 'misunderstood,' and 'discomfort.' You could think of it like playing Tetris where you must match shapes of blocks that fit together. Another way of going about it is to combine the sound and meaning of two already existing words, the so-called 'portmanteau words,' such as 'ginormous' (gigantic + enormous). In other cases, new words originate when humans imitate a naturally occurring sound in nature – which explains why animal sounds differ between languages.