Which is correct:
I am excited to see these guys growing up.
I am excited to see these guys grow up.
Having hard time figuring out how to use gerunds in a sentence.
They’re both acceptable, and largely interchangeable. In this case, there’s a slight difference of emphasis in that growing up shows more interest in the process, and grow up more interest in the result. So the former means the pleasure would come from seeing the “guys” as they grew and learnt new things, while the latter refers more to the pleasure of seeing what kind of adults they grow into.