日本語

[Nick]

Prof. Frank Stajano (of the computer science department at Cambridge University) made some flash cards to help learn kana:
https://www.cl.cam.ac.uk/~fms27/goodies/fms-kana.pdf

[Nick]

Small Numbers
For the integers from 1 to 10, traditional names of native Japanese origin are often used:
ひとつ (hitotsu) 1
ふたつ (futatsu) 2
みっつ (mittsu) 3
よっつ (yottsu) 4
いつつ (itsutsu) 5
むっつ (muttsu) 6
ななつ (nanatsu) 7
やっつ (yattsu) 8
ここのつ (kokonotsu) 9
とお (tō) 10
(You may have expected "tō" to be written in hiragana as とうbut in this word the long 'o' is spelled
"oo" instead of "ou" for historical reasons.)
When counting off (e.g. in a gym), these usually get shortened:
hi/hī/hito, fu/fū/futa, mi/mī, yo/yō, i/ī/itsu, mu/mū, na/nā/nana, ya/yā, koko/kono/kō, to/tō.

Main System
The main system for counting is of Chinese origin.
For 0, we say れい (rei) or use the foreign loan word ゼロ (zero).
(Note the use of katakana for foreign words.)
People also use まる (maru), which means circle, particularly when reading out digits individually.
いち　(ichi) 1
に (ni) 2
さん (san) 3
よん (yon) or し (shi) 4
ご (go) 5
ろく (roku) 6
なな (nana) or しち (shichi) 7
はち (hachi) 8
きゅう (kyū) or く (ku) 9
じゅう (jū) 10
ひゃく (hyaku) 100
せん (sen) 1000
Where 2 names are listed above, the first is more commonly used.
In many situations either may be used, but there are some cases in which one of them is standard.
Any integer from 1 to 9999 can be constructed from the above:
Thousands part: (digit) せん
Hundreds part: (digit) ひゃく
Tens part: (digit) じゅう
Units part: (digit)
but missing out any part that is 0 and any digit except units that is 1.
Moreover, awkward consonant combinations get modified as follows:
300: say さんびゃく (sanbyaku)
600: say ろっぴゃく (roppyaku)
800: say はっぴゃく (happyaku)
3000: say さんぜん (sanzen)
8000: say はっせん (hassen)

Examples:
101 is read ひゃくいち (hyaku ichi)
2340 is read as either にせんさんびゃくよんじゅう (nisen sanbyaku yonjū) or にせんさんびゃくしじゅう (nisen sanbyaku shijū).

Larger numbers
In English, we learn the integers from 1 to 999 and then add new words for 10^3 (thousand), 10^6 (million) etc.,
splitting the decimal representation into 3 digit groups.
In Japanese, we learn the integers from 1 to 9999 and then add:
まん (man) for 10^4,　おく (oku) for 10^8 etc.
(For example, 100000 is seen not as "one hundred thousand" but as "ten ten-thousands".)
Unlike the tens, hundreds and thousands, we do use the digit 1 with these,
e.g. 10000 is いちまん (ichiman) and not just　まん (man).
We also use the digit 1 in front of せん (sen) if it comes directly before one of these powers of 10^4,
and the awkward combination いちせん (ichisen) is modified to いっせん (issen).

Kanji
Our Arabic numerals are usually used in horizontal Japanese writing but kanji may occur in vertical writing.
As with Arabic numerals, the first three are just the corresponding number of bars, but with kanji we lift our
pen (or brush) completely from the paper between them instead of joining them up.
一 1
二 2
三 3
四 4
五 5
六 6
七 7
八 8
九 9
十 10
百 100
千 1000
万 ten thousands (man)
億 hundred millions (oku)

Counters
When counting objects, the small numbers of Japanese origin that we saw first can be used directly
(as in English), but with the main numbers (of Chinese origin), units are always required.
Thus instead of "6 cows" we say "6 head of cattle" (also possible in English),
and instead of "6 pencils" we say "6 sticks of pencil" (not really possible in English).
The units in this extended system are known as counters, and there are lots of them!
Here are a few of the most important:

Write 本 say ほん (hon)
As a noun, this means book.
As a counter, it means sticks, i.e. any long, thin objects.

Write 枚 say まい (mai)
This means sheets, i.e. any thin, flat objects.

Write 杯 say はい (hai)
As a noun, this means cup (for alcohol or in sport).
As a counter, it means cupfulls.

Write 冊 say さつ (satsu): counter for books.

Write 頭 say とう(tō): counter for large animals.

Write 匹 say ひき (hiki): counter for small animals.

Write 個 say こ(ko): a general counter for small articles.

Write 人 say にん(nin)
As a noun, this means person.
It is also the counter for people, but 1, 2 or 4 people are read differently:
Write 1人 say ひとり (hitori)
Write 2人 say ふたり (futari)
Write 4人 say よにん (yonin).

[Nick]

By the way, anyone interested in Japanese mathematics as it was while
Japan was still largely isolated from the outside world should take a look
here: https://www.ndl.go.jp/math/e/introduction.html

[Batalov]

Originally Posted by LaurV

Interesting, we are not keen to learn Japanese right now (we struggled with Korean on Duolingo for a while, nice course! but gave up due to lack of time and intellect), but we read everything Nick posts, and follow his links, as we knew from the past that he is not talking bullshit, and when he talk, you better listen...

So, following his links, and links from there, we learned today about the concept of mora/morae. We didn't know about them, and could not imagine that there is a speech unit larger than a sound and smaller than a syllable.

Very new to me, too, and today I learned it via a google suggestion (a very nice one) -

[Nick]

Originally Posted by Batalov

Very new to me, too, and today I learned it via a google suggestion (a very nice one) -

Nice! Coupled with the strict timing of morae, it is important to learn how accentuation in Japanese is done using pitch:
Japanese pitch accent