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I have some doubts about the usages of That and Who. Sometimes I read sentences such as. "You are someone I love" "You are someone WHO I love" Or "People were asked to describe the qualities they look for in a friend" "People were asked to describe the qualities THAT they look for in a friend"
Why in some of these sentences WHO or THAT are omitted and others are not. Could somebody help me with this? I'll appreciate it! Thanks a million.