How to tell if this dude likes me?

So this dude I work w is kind of confusing like one minute he’s hot the next cold. I’d say pretty introverted. But anyways I’m wondering does he like me? Ex: sometimes he’ll be in my space when he doesn’t need to be Ex: he now says thank you when I do small things for him even tho he never used to say that too me before Ex: he’ll help me in subtle ways like move things out of the way if he notices I’m struggling to do something. But very subtle, think I wouldn’t notice type of thing. But these actions of his are pretty rare and it’s on his “hot days” that he will do this. -Ex: but other days he’ll completely ignore me and not do anything to be near me at all. But he hardly talks even on his hot days. Can someone explain this?

Side note: he’s pretty introverted in general so…