No one wants to be tagged as a newbie. Repetition of words or sentence structure shouts to an editor you don’t
know what you’re doing.
An example of word repetition: Raspberries taste best right off the bush. Ways to serve raspberries include: raspberry pie, raspberry crisp, raspberry crepes. Others tell me they like their raspberries on breakfast cereal, yogurt, and with ice cream.
A bit over the top, but you get the point. Writing this same paragraph using the word raspberry only once is a challenge, but it can be done. Try it.
Sometimes we write using repetition thinking we’re making our point stronger. In fact, repeating words takes away from what we’re trying to say. Example: Texting while driving causes accidents—accidents which are entirely unnecessary.
When speaking, this repetition would work. Not for the reader.
Another form of repetition is in sentence structure. All complex or all simple sentences can create a dull piece. The reader may not even realize what is bothering them about the writing. By mixing up your sentence lengths and complexities, you create interest.
Once I edited a book where almost every sentence began with a gerund (a word that begins with –ing). Most of us would catch this right away in our own writing, but we might not notice overuse of words like but, and, or as.
To catch repetion read your material aloud to someone else. I highly recommend a writing group.