Well, two different moments in the movie have been on my mind a bit... and the topic fits in this thread well enough. It's about a handful of lines that seem simple but seem to reveal quite a lot, although "double meanings" might not play into this so much. So, I'll post it here in any case.
Someone somewhere once noted that when Jack is talking to Lureen about Bobby's teacher he says "I complain too much." And the person who originally pointed this out said that this seems to be a quick moment where Jack is verbalizing one of his key character traits. He does complain and bitch quite a lot, as we all know.
So, it recently occured to me that a similar thing might happen with Ennis. A moment where he verbalizes something that is a major part of his character. During the painful post-divorce conversation with Jack, Ennis says "I don't know what to say...", which seems to be one of his defining characteristics (his silence, his difficulty expressing himself verbally, etc.). And then, when he tells Jack sorry, he says "you know I am" and then seems to try to give Jack a meaningful look in the eye. I think this might be some evidence of how much Ennis (throughout their relationship) relies on Jack to be able to read his very subtle signals, to understand him without Ennis having to verbalize things. He expects Jack to know him so well that he'll understand what Ennis means intuitively. Sometimes it seems like they can both sort of read each other's signals, thoughts and emotions. But, it seems like there are just as many times with their signals get crossed or confused. It's interesting how many questions and remarks that Jack puts to Ennis - and vice versa- how many statements Ennis makes to Jack - where they don't directly answer one another... or seemingly switch subjects... or just don't answer (verbally at least).
It's funny now that I think about it. It seems like the "I don't know what to say..." line is the flip side of what Ennis tells Alma as he's rushing out of the apartment with Jack during the reunion scene. He tells Alma that they might be gone all night because they might "get to drinkin and talkin"... Here's a moment where Ennis is hoping that Alma might believe that he's a talkative enough fellow to actually be able to stay out all night shooting the breeze. I've always found that funny and cute.