#1 is common, but erudite. People who use such a term are also likely to use other Latinisms. Since you are a well educated person, it would be worth your time to learn some Latinisms. They make a fabulous impression, but use them sparingly, not to show off, and only with the right audience to make careful arguments. They are not for casual conversation. There are dozens, but here are a few: "post hoc ergo propter hoc" "de facto" "caveat emptor" "quid pro quo" #2 "IN the cards" is very common. I wouldn't say "on the cards" but somebody else might. "On the cards" is an expression I would only use in connection with fortune telling. #3 "Bore the _____ off someone" will be understood no matter what word you put in the blanks, but "pants" is very common. I would be more inclined to use "living daylights", or "bejeebers" or some similar nonsensical sound if I wanted to be imaginative. You can invent any sound that pleases you.

‘Sine qua non’ is used in legal discussions, not in general conversations. ‘In the cards’ is used in American English. ‘On’ sounds strange to me

'Sine qua non,' you might hear in intellectual circles, academics, or certain podcasts. But it would be very unlikely to hear it in any kind of normal situation. We say 'in the cards,' somewhat regularly in the US, but I've never heard 'on the cards.' You can hear the negative version, maybe, even more often. Like if something didn't work out for me, I could say 'Ah, that's okay, it just wasn't in the cards.' It speaks to luck or fate. 'Bore the pants off someone' is still somewhat used, but it sounds kind of antiquated. Like it was probably more popular in the 90's. Although if you're in a workplace or amongst people ages 40-60 in the US, it'd be understood by most people.

Hi Yazdan! Let’s go through these expressions: 1. Sine qua non: You're right—it’s a Latin phrase and typically used in more formal or academic contexts. It's not as common in casual conversations, but it's familiar to those in specific fields (like law, philosophy, or academia). It’s more of a specialized term than a widely-used expression. 2. On the cards: This one is a more figurative expression and does pop up in everyday conversation. It means something is very likely to happen or expected. It’s common in British English and not as much in American English, but you will still hear it in both varieties. It’s not a phrasal preposition, but more of a set phrase. 3. Bore the pants off someone: This is a casual, idiomatic way to say that something is very boring. It’s quite common in informal settings and would definitely come up in daily conversations, especially among native speakers. It’s less formal, but it’s definitely used by many. And you're spot on about listening—abundant listening can definitely help improve the naturalness of your expressions! Reading is helpful, but listening to native speakers in conversations can really give you a feel for these kinds of phrases. Let me know if you’d like more examples or explanations! 😊

2 and 3 are common, in England at least. You won’t hear the first.