조차 — not even that but

This expression is used to express "not only others but also the most primary one". Generally, it refers to extreme situations that the speaker either did not expect or could not anticipate.

Details

1. This expression sounds most natural when used with negative statements. It can therefore sound awkward if used in positive situations.

세주 씨는 한글조차 읽어요. ✕

2. The expressions 까지 and 도 can be substituted for 조차. However, it should be noted that 조차 carries the added nuance of "the worst possible case".

더운데 바람까지 안 부네요.

3. This expression is often used together with -은/는커녕, which indicates the negation of not only one thing but also something else on an even more telling, or serious level.

우리 엄마는 해외여행은커녕 제주도조차 못 가 보셨어요.

Our mother has never even traveled to Jeju Island, let alone overseas.

책을 읽기는커녕 신문조차 못 볼 때가 많아요.

There are times when I can't even read the newspaper, not to mention books.

4. When used together with a verb, the form -(으)ㄹ 수조차 없어요 is used.

다리가 너무 아파서 일어설 수조차 없어요.

I can't even stand since my legs hurt very much.

제 조카는 5살인데도 제가 안을 수조차 없을 정도로 아주 커요.

Even though my nephew is just a 5 year-old kid, he's so big that I cannot even hold him.

Kimchi Reader

Used to emphasize that something is not even as much as something else. An inclusion of extreme cases that are generally hard to predict. The one attached to 조차 is the most important.