In this section, we'll learn various ways to express the minimum expectation. This grammar is not used as often as you might think as there are many situations where a simpler expression would sound more natural, but you should still become familiar with it.
In English, we might say, "not even close" to show that not even the minimum expectation has been met. In Japanese, we can express this by attaching 「さえ」 to the object or verb that miserably failed to reach what one would consider as a given. Let's see some examples of this with nouns first. You can also use the same grammar in a positive sentence to show that that is all you need to produce a desired effect.
For nouns only, you can add 「で」 and use 「でさえ」 instead of just 「さえ」. There are no grammatical differences but it does sound a bit more emphatic.
You can also attach 「さえ」 to the stem of verbs to express a minimum action for a result. This is usually followed up immediately by 「する」 to show that the minimum action was done (or not done in the case of negative).
「（で）すら」 is a variation of 「（で）さえ」 that means essentially the same thing and is used in the exact same way. However, it is more obscure and is usually ignored in favor of 「（で）さえ」. The main reason we are covering it here is because since it's the same as 「（で）さえ」, it's a cinch to go over. Plus, it's covered in the Japanese Language Proficiency Test (JLPT) level 1 (if you're thinking of taking that).
I suspect this grammar comes from the adjective 「愚か」 which means to be foolish or stupid. However, in this case, you're not making fun of something, rather by using 「おろか」, you can indicate that something is so ridiculous that it's not even worth considering. In English, we might say something like, "Are you kidding? I can't touch my knees much less do a full split!" In this example, the full split is so beyond the person's abilities that it would be foolish to even consider it.