one long object; one film or program; one call; one goal or hit
The numeral-counter form for 本: used for long or cylindrical things, and by extension for films, TV programs, phone calls, goals, home runs, and similar countable events.
See also: 本 (ほん)
Please give me one bottle of beer.
I watched one movie over the weekend.
I'll make one phone call later.
one textual version; one book or manuscript copy; a certain book
Limited use for a single book, manuscript, copy, or version, especially in textual or bibliographic contexts. For an ordinary modern 'one book,' 一冊 is normally the learner-safe choice.
In editing the text, they consulted one other manuscript copy.
One variant version with a different ending has been handed down.
ippon; one point; decisive blow
Martial-arts scoring term, especially familiar from judo and kendo. It can refer to a decisive point or to the valid strike or throw that earns it.
In the final, he scored an ippon with a shoulder throw.
A sharp valid strike landed on the head.
Specialized traditional term from the geisha world; rare outside historical, cultural, or hanamachi-related contexts.
See also: 半玉 (はんぎょく)
In older language of the geisha world, 一本 can refer to a geisha.
single-minded focus on; devoted solely to
Used after a noun, often in patterns such as 〜一本で and 〜一本に, to mean concentrating on that one thing and not branching out.
He has come this far by devoting himself solely to baseball.
After graduation, I intend to focus solely on research.
I gave him a quick call before leaving.
He makes his living solely from fishing.
There's only one road through the village.
He scored a beautiful ippon against his opponent in the final.
一冊 is the everyday counter for a bound book or volume, while 一本 for a book is a narrower, more bookish usage limited to manuscripts or textual versions.
一つ is the general, all-purpose way to say 'one thing,' whereas 一本 is reserved for long, cylindrical objects or specific idiomatic counts like calls and goals.
fishing with a pole; pole fishing
solitary pine tree; single pine tree
sticking to one thing; single-mindedly; never deviating from · one's sole talent; one's only forte
single-minded; one-track mind
log bridge; single-log bridge
unification; consolidation; integration
finger; one's finger
solitary Japanese cedar
Standard kanji spelling. Used both for the counter expression 'one ...' and for the more idiomatic or specialized noun uses.
Arabic-numeral spelling often used when the meaning is an actual count or score, such as one bottle, one film, or one point. The kanji spelling is safer for idiomatic and traditional uses.
Formed from 一 'one' plus 本, the counter used for long objects and several extended categories. The reading いっぽん reflects the regular sound change from いち + ほん to いっぽん.
single-toothed geta; tall geta with one tooth
unibrow; monobrow
single chopstick stuck upright in rice offered to the deceased
long unbroken stool; sausage-shaped poop
straight road; direct unforked road
straightforwardness; honesty; purity
winning by an ippon; winning by a point