Can I say just "open" instead of "open up"?
Native speaker’s answer
Rebecca
No, in this case, it would sound a little awkward if you replaced "open up" with "open". This is because "open up" is a phrasal verb and has a slightly different meaning than "open". To "open up" here means to reveal or communicate something better or in a more honest and comfortable way. Ex: She won't open up about her childhood. Ex: I'm trying to get the students to open up, but they are all very shy.