以下

That's a great question, and it trips up many learners! The key difference is whether the number itself is included. 以下 (ika) means 'less than or equal to', so the number is included. For example, 10以下 would include 10. 未満 (miman) means 'strictly less than', so the number is not included. 10未満 would mean up to 9, but not 10.

Think of it like this:
以下 (ika) = ≤ (less than or equal to)
未満 (miman) = < (strictly less than)

Yes, absolutely! While it's very common with numbers, 以下 (ika) can also be used to mean 'below' in a non-numerical sense, often referring to a point in text, a physical location, or even a hierarchy. For instance, you might see '以下の点にご注意ください' (ika no ten ni gochuui kudasai) meaning 'Please note the points below'.

Sure! Here's a simple example:

500円以下 (go-hyaku en ika)
Less than or equal to 500 yen / 500 yen or less

So, if a sign says '500円以下の商品' (go-hyaku en ika no shouhin), it means 'items costing 500 yen or less'.

For 'less than or equal to' (where the number is included), 以下 (ika) is the primary and most common term. For 'strictly less than' (where the number is NOT included), 未満 (miman) is the word you'll use. So, they work together to cover both scenarios.

The opposite of 以下 (ika), which means 'less than or equal to', is 以上 (ijou). 以上 (ijou) means 'greater than or equal to' or 'more than or equal to'.

So, if 以下 (ika) is ≤, then 以上 (ijou) is ≥.

For practical purposes, 以下 (ika) always includes the number or reference point it's attached to. This is its defining characteristic when compared to 未満 (miman). You can rely on that rule.

That's a good observation! '以下同文' (ika doubun) is a set phrase that means 'the rest is the same' or 'the following text is identical'. You often see it in official documents or forms where a section repeats information from an earlier part. It's a specific usage of 以下 (ika) in a non-numerical context.

以下 (ika) is a neutral term in terms of politeness. It's used in both formal and informal contexts. You'll find it in official documents, news reports, and also in everyday speech when you're talking about limits or ranges.

Yes, you can! For example, '18歳以下 (juu-hachi-sai ika)' would mean '18 years old or younger'. If you wanted to say 'strictly younger than 18', you'd use '18歳未満 (juu-hachi-sai miman)'.

You're spot on! '以下略' (ikaryaku) is another common phrase using 以下 (ika). It means 'abbreviated below' or 'details omitted below'. It's often used when quoting something long, and you're just showing the beginning and then indicating that the rest has been cut for brevity. The 以下 (ika) still points to 'the part that follows'.