A big thing to remember is that despite actually caring about his friends deep down inside, and having something vaguely resembling a conscience (sometimes?), he hedges around actually being sincere verbally almost constantly. Every kindness in the form of material goods is offered to others at a nominal price or added to someone's tab. At most, during a special or very terrible occasion he seems to give friends very minuscule discounts he doesn't give others, or at least offers to sell them the really good stuff he has tucked away. Most of the advice he offers others (and he does tend to offer it unasked but hey he's a bartender) is very Ferengi and equates to "be selfish."
But in it's weird way, that is him being sincere? He rarely ever openly says things about how fond he is of others, but if he gives very Ferengi advice to someone he likes to just look out for themselves, he's hoping they actually do because he thinks they deserve to look out for themselves. Quark cares about his friends, but a lot of that translates to trying to get them to act more Ferengi, because then they'd focus more on their own self-interest. The idea that he should selflessly act in their interests is alien and even though he does it sometimes, he tries to avoid it, usually viewing it as that he's getting overly influenced by being around Starfleet people and hyoo-mons too much.
An example of him caring about someone else's profit is in "You Are Cordially Invited." When Jake talks about getting published, Quark initially is excited for him until he says he's not getting paid and then Quark acts as if he's almost offended on his behalf and gives him his sympathies. It's clear that Quark thinks Jake deserves profit for it, which is really the best thing a Ferengi can think of someone else.
As far as his patterns of speech go, he's very dry and sarcastic. He doubles back on a lot of his more sincere or selfless words to people to prove a point a lot. In the same example, when Jake says his stories were "bought" then backtracks and says it was just a figure of speech, Quark offers him a free round and when Jake asks "Really?" he says "No, it was a figure a speech" just to sass him. Quark likes to play with other people's words and quite often will say things that sound completely sincere and then backtrack and admit he was lying, but it's usually to make some kind of sassy point.
WHOO sorry this got long but I just got done a rewatch. I hope it helps!
Re: Quark | DS9
But in it's weird way, that is him being sincere? He rarely ever openly says things about how fond he is of others, but if he gives very Ferengi advice to someone he likes to just look out for themselves, he's hoping they actually do because he thinks they deserve to look out for themselves. Quark cares about his friends, but a lot of that translates to trying to get them to act more Ferengi, because then they'd focus more on their own self-interest. The idea that he should selflessly act in their interests is alien and even though he does it sometimes, he tries to avoid it, usually viewing it as that he's getting overly influenced by being around Starfleet people and hyoo-mons too much.
An example of him caring about someone else's profit is in "You Are Cordially Invited." When Jake talks about getting published, Quark initially is excited for him until he says he's not getting paid and then Quark acts as if he's almost offended on his behalf and gives him his sympathies. It's clear that Quark thinks Jake deserves profit for it, which is really the best thing a Ferengi can think of someone else.
As far as his patterns of speech go, he's very dry and sarcastic. He doubles back on a lot of his more sincere or selfless words to people to prove a point a lot. In the same example, when Jake says his stories were "bought" then backtracks and says it was just a figure of speech, Quark offers him a free round and when Jake asks "Really?" he says "No, it was a figure a speech" just to sass him. Quark likes to play with other people's words and quite often will say things that sound completely sincere and then backtrack and admit he was lying, but it's usually to make some kind of sassy point.
WHOO sorry this got long but I just got done a rewatch. I hope it helps!