You're having a deep talk with a close friend about your
parents. You told your friend that your parents set high
standards for you, but you didn't meet them. You think your
parents are probably sad that you haven't been more successful
in life. You tell your friend: They're probably disappointed in
me. Use "probably" to talk about something that you think is
true, but you're not sure. "Probably" describes a probability
anywhere from 50% to 99%. Use "probably" with an adjective:
You're probably exhausted. You can also use "probably" with a
longer phrase that acts like an adjective: He's probably on his
way. And it also can be used with a verb: They probably left to
go get some food. When you're "disappointed", it means that
you're a little sad because something wasn't as good as you
expected it to be. You can be "disappointed with" a movie, a
sports team's performance, and so on: Betty was kind of
disappointed with how her cupcakes turned out. But when you say
that you're "disappointed in" a person, it means