I submitted my UC application earlier today, and was just reviewing when I noticed that I may have made a mistake! 
On the About You, Personal Information section, it asks you to put in the languages that you speak. My native language is Serbian, so I put that in for “First Spoken Language”, but I never saw an option to add in a second language. I didn’t want to put “English and another language” as my “First Spoken Language” because I technically didn’t learn English until I was 5, so it counts as a second language instead of first. But now my application has “First Spoken Language: Other:Serbian”, while the “Second Spoken Language” box is blank!
I mean, it must be implied that I do speak English, and I even mentioned in one of my personal insight responses that I speak four languages including English, but would this mistake hurt my chances of admission? I don’t want them to think that I don’t speak English since I was not able to list it as my second language. :((((
They’ll probably notice it, and realize it (assuming you wrote your essay in English).
If you’re really that worried about it, contact the admissions office and inform them of it. I don’t think it’ll ruin your application, though.
Seriously?
You’re at a US hs, dont think they’ll know you’re comfortable in English?