Recently the exact match keyword has been modified by Google. The exact match keyword will begin to serve to search terms that are “close variant”. Search terms with the same meaning as the keywords, regardless of their slight variations, will trigger the ads. In this way, you can have an effective campaign without creating an all-inclusive list of keywords to ensure high impression rate.
For example, if your exact match keyword is “shoes for men”, your ad may show on searches for “shoes men” and “men shoes”. However, searches for “red shoes for men” will not trigger the ad to appear as these are different from the search intent of “shoes for men”.