Decisive and divisive are easily confused words.
The spell-check application of most word processing software programs would not catch a slip-up of these two words. Spell-check is looking for words that aren’t in its dictionary, and words that resemble words in its dictionary but are possibly spelled wrong. Spell-check isn’t perfect. It doesn’t know and can’t guess what word you wanted or what word you meant, it can only judge the words on the page. If you used words that are all spelled correctly, it gives you a pass anyway.
Autocorrect suggests words that start with the same letters. It’s suggesting what word you may want to save time, but quite often, its suggestions are pretty off base. They don’t help you out, but they do make you laugh.
Decisive (pronounced “dee-sy-siv”) is an adjective. It describes someone who surveys their options, quickly picks one, and moves forward without hesitation or reconsideration.
Divisive (pronounced “dee-vI-siv”) is an adjective. It describes someone who aims to create divisions, problems, controversy, and likely, chaos.
The following story uses both words correctly:
Devlin was credited with being a great leader because he was decisive, so the team could move forward on many projects. He was also criticized for being divisive by team members who disagreed with his decisions; these team members felt he didn’t consider potential setbacks or roadblocks before moving forward.