Even in English, they help me understand what I'm watching better. I'm trying to learn Spanish right now, but I know that I can't use them in real life, so I don't use them. They are definitely helpful though.
Sometimes. I had to last night when I was watching The X-Files on Netflix, I got like halfway through an episode and realised I had no idea what was going on, my mind had just wandered
Yes. If I'm watching something in Spanish or German I only have the subtitles in the respective languages, never English. But if I'm watching something in English or another language that isn't Spanish or German, I put the subtitles in English.
During Chemistry sophomore year, I sat in the back and I never cared about the class, so I would pull out my phone and watch Netflix (specifically Charmed) with the subtitles on since I wasn't able to put my headphones on for obvious reasons. That developed my obsession with subtitles.
I use them as insurance and I use them only in English.
For series I don't want to get spoiled, like Game of Thrones, HTGAWM, Scandal, AHS, The Good Wife, I watch them as soon as they air so I don't usually use subtitles for them. Also I rarely need subtitles for comedy series since they are easier to understand.
