越是 is used in the pattern 越是X越是Y (or with a single 越是 + 越) to express 'the more X, the more Y', indicating that two things increase or change together in the same direction. It works as a verbal phrase that typically precedes a verb, adjective, or noun. This structure is common in both spoken and written Chinese for emphasizing a proportional relationship or a cause-effect link where one condition intensifies the other.