One form of redundancy involves rephrasing a previous sentence. For example:
If we are going to succeed at contest, we're going to have to put more effort into our practices. We're not doing enough work at rehearsal, so we need to try harder if we plan to remain in the top five.
Notice how the following revision reduces the repeated phrases into a more concise statement:
If we are going to remain in the top five at contest, we need to put more effort into our practices.
Another type of redundancy involves repetition words and phrases. For example, "the end result" is a commonly used phrase, but "the result" is sufficient. "At this point in time" is another example; "now" usually is sufficient. Yet a third example is "each and every"; "each" is sufficient. Rudolph Flesch's book The ABC of Style provides numerous examples of repetitious phrasings and gives advice on how to simply the expressions.
A third example of redundancy is writing numbers both as words and as equivalent Arabic numbers in parentheses.
There are four (4) men in a quartet.
The Arabic number in parentheses is unnecessary. In fact, all numbers 10 or greater are written in Arabic form.