The reason for writing is to communicate, even if only with oneself.
I often see writing where the writer seems to have forgotten their purpose, and appears to be writing to display their intelligence, vocabulary or to otherwise attempt to impress. This does not aid communication.
If the reader feels they need to have swallowed a dictionary, they’ll give up.
Complicated sentence structures give the reader another reason to give up. The writer might be falling into their own grammatical traps, getting tangled up, making mistakes, generating ambiguity. Mistakes do not make a writer look intelligent. Ambiguity does not deliver the message. It’s far more impressive to write simply and correctly. Just look at Ernest Hemingway’s books: his themes are not simple, yet his style is both simple and evocative.
‘One should aim not at being possible to understand, but at being impossible to misunderstand.’ – Quintilian
Venturing into a thesaurus to add variety to writing is a good idea, but also fraught with the danger of choosing a word with a different meaning, or one that is so obscure it won’t be widely understood. The thesaurus will have several lists of alternatives, according to the sense of the original word and what type of word it is. Because we love to use nouns as verbs, parts of verbs as adjectives etc. in English, it’s easy to pick the wrong word. Choose carefully. Don’t select the first word that sounds interesting.
If an everyday word has exactly the right meaning, why not use it? Everyone will understand it. However, if a less common word is just right, and a simpler word is not, go for it.
I often see words that aren’t quite right. They might sound similar to the correct word, but mean something completely different. This could be because of a typo, and the spell checker has made its best guess at the word, but offered something quite inappropriate. Take care with its suggestions! If you have any doubt about a word’s meaning, look it up in a reputable dictionary. This will improve your writing for ever.
Another thing to keep in mind is the length of a text. We receive a mountain of emails, and read articles and posts online. There’s so much to read that there isn’t time for it all. A piece only needs to be as long as necessary to fulfil its purpose. Once you’ve said what you have to say, stop.