Lyric discussion by Enitharmon 

Cover art for Sort Of lyrics by Silversun Pickups

Sounds like it's about being in love with someone who is troubled.

"What's keeping my tongue tied? I see when you roll your eyes. I swear any moment you will hear my spirit explode"

To me that line speaks of the troubled person completely resenting the singer's love / presence / advice / help... or whatever. The singer recognises this resentment and wants to speak out because it's hurting them.

Also, the whole fire on the ground / wheel in the lake / smoke in the sky thing. They sound like metaphors for these troubles the other person might be going through. And the singer is saying like... why should i care? "Should it turn my whole world around?"

The singer is unsure about whether they can help this person who doesn't want to be helped "When your hand stretches out... is is way beyond my reach?"

Also, the troubled person is taking advantage of the singer's interest (sexually, probably) "do you think it's sort of a crutch, when you try to move me to touch" which is ruining the love the singer has for them, but not their lust... "so i shake, well sort of, but not much" "does it make you nervous when you hear my bones, animate my body, without my soul?"

I don't know if i've explained that very well, but it makes sense to me.

Singer is in love with troubled individual. Troubled individual does not / cannot return these feelings. The singer is gradually becoming emotionally numb. But they stick around anyways for the sex...

"Do you think i'm sort of alive? Should i set these motives aside?"