What does this mean? Ce qui s’est passé le jour du spectacle. It tells me to answer this question. I don't understand....does it mean "what happened during the spectacle" or "what happened in the day of the spectacle" I don't understand :(

Difference between 'ce que' and 'ce qui'? I can't tell the difference. Something subject and direct object...a slight difference? I really don't understand, even though I did some prior research already. I look at the sentences and the usage of 'ce que' and 'ce qui' look the same to me.

Ça me vs C'est For example, "ça en vaut de plein" means "it is worth it", right? But...well, I know ça works like cela and is different from "ce". But still, I don't understand when to use c'est or...I find it confusing when suddenly the text uses ça. So what is ça en? How is it different from 'c'est', and how am I going to use them? (sorry, the title means ça en vs c'est) Thank you!

Is 'Strike the iron when it is hot' idiom originally from Chinese? I'm pretty sure it is because 趁熱打鐵 is so common. But I researched but can't find anything! I just ownder if there are some common english idioms that come from Chinese.

Pushed the door opened/open? ...and soon we were pushing heavy oaken doors OPEN/OPENED? I checked google and they both seem to exist? I am very confused. Thanks!

The grass are so nice/the grass is so nice? Ok, that is obvious 'is'. But what about: "Nice grass! They are so cute?" OR "Nice grass! It is so cute?" Both seems a bit off. Let's just say I NEED to comment that they are cute/it is cute. Which one is correct? I heard that grass kind of singular, like fish. But should I grass 'they' or 'it'? Normally I'd use 'is'...but it seems strange to call a lawn of grass 'it'. Thank you!

But when all I see WERE/WAS Carly's trees? When all you see WERE Carly's trees... When all you see WAS Carly's trees, you stop thinking about.... Was or were? Is 'all you see' singular?

How do you say this in English: 農曆逢四、九都會趕集/ 农历逢四、九都会赶集？ Thank you, erudite folks!

Was or Were for this sentence? It was my graduation day, but apparently meeting Judy and teaching her algebra WERE so important that they had completely forgot about it. or should the 'were' be 'was'? It was our graduation day, but apparently meeting Judy and teaching her algebra WAS so important that they had completely forgot about it. Should I use was or were?