足たす

た

す

Common wordJLPTN4Freq.FrequencyTop 20,000

足す · godan verb (-su)

Form	Positive	Negative
Dictionary	足たす	足たさない
Polite	足たします	足たしません
Past polite	足たしました	足たしませんでした
Past	足たした	足たさなかった
Te-form	足たして	足たさないで
Desire	足たしたい	足たしたくない
Potential	足たせる	足たせない
Passive	足たされる	足たされない
Causative	足たさせる	足たさせない
Causative passive	足たさせられる	足たさせられない
Volitional	足たそう
Polite volitional	足たしましょう
Imperative	足たせ	足たすな
Conditional	足たせば	足たさなければ
Tara conditional	足たしたら	足たさなかったら

Meanings

godan verb (-su), transitive verb

add (numbers); sum

Specifically for arithmetic addition. Used with numbers, amounts, or mathematical expressions.

5に3を足たすと8になる。
If you add 3 to 5, you get 8.
消しょう費ひ税ぜいを足たした金きん額がくを計けい算さんしてください。
Please calculate the amount with consumption tax added.

godan verb (-su), transitive verb

add (something); top up; supplement

General sense of adding something extra to what already exists: ingredients, liquid, items, etc. Often used when topping up or supplementing.

味あじが薄うすいので、塩しおを少すこし足たした。
The flavor was weak, so I added a little salt.
コーヒーが少すくなくなったので、お湯ゆを足たしておいた。
The coffee was running low, so I topped it up with hot water.

godan verb (-su), transitive verb

take care of (business); do (one's business)

Used in the fixed expression 用を足す, meaning to run an errand or, euphemistically, to relieve oneself. Not freely productive outside this phrase.

Usage patterns

〈数かず〉に〈数かず〉を足たすto add one number to another
3に5を足たすと8になる。
If you add 5 to 3, you get 8.
〈物もの〉に〈物もの〉を足たすto add an ingredient or item to something
スープに塩しおを少すこし足たした。
I added a little salt to the soup.
〈場ば所しょ〉に〈物もの〉を足たすto top up a place with more of something
お風ふ呂ろにお湯ゆを足たした。
I added more hot water to the bath.

Expressions

用ようを足たすrun an errand; take care of business · go to the toilet; relieve oneself
腹はらの足たしsomething to fill one's stomach; a bite to eat
足たしにするsupplement; make up for a shortfall; put towards
足たしになるbe of help; be useful; go toward
足たして二にで割わるcombine and average; compromise; split the difference

Kanji

足leg, foot, be sufficient

Related words· 6

加くわえるN3sense 2
加える is more formal and often used for adding abstract things like conditions or changes, while 足す is casual and typically used for concrete items or numbers.
増ふやすN3sense 2
増やす means to increase the quantity or number of something overall, while 足す means to add a bit extra to reach a needed amount.
付つけ加くわえるN1
足す is typically used for adding numbers or a small quantity of something, whereas 付け加える is about supplementing content, words, or information.
プラスN3
プラス is a noun/conjunction borrowed from English used for adding numbers or ideas, while 足す is the native Japanese verb meaning 'to add' and takes normal verb conjugation.

Show 2 more

寄よせるN2
足す is the ordinary modern verb for adding numbers, while 寄せる's numerical sense is limited and mostly abacus-related.
継つぐN2
足す is a general word for adding more of something, while 継ぐ is used specifically for replenishing fuel or picking up a conversation to keep it going.

Opposites

引ひくN5sense 1
引く means to subtract a number, the opposite arithmetic operation to 足す, which means to add a number.

Don't confuse with

足たし
足す is the verb meaning 'to add', while 足し is its noun form referring to something that supplements or helps make up a shortfall.

Word family· 17

足たし
supplement; top-up; making up a deficiency
足たし算ざんN2
addition
付つけ足たし
addition; supplement; appendix; postscript
付つけ足たすN1
add on; append; supplement
継つぎ足たし
adding to; extending; topping up

Show 10 more

用よう足たしN1
running errands; going on errands · taking care of business; doing business · going to the toilet; doing one's business · purveyor; purveying
足たし前まえ
supplement; addition; extra amount
足たし湯ゆ
adding hot water to a bath
塗ぬり足たし
bleed (printing)
描えがき足たす
add to a drawing; draw in additional elements
書かき足たす
add to a written text; write in more; tack on
注つぎ足たし
refilling; topping up
注つぎ足たす
top up; replenish
継つぎ足たす
extend; add to; supplement
言いい足たす
add something to what was said; say additionally

See all 17 in Explore →

Written forms

足たすUsage83%
Standard kanji spelling for all senses.
たすUsage17%
Kana spelling is common in casual writing and when the mathematical sense is clear from context.

Etymology

Derived from the verb 足る (たる, 'to be sufficient') with the causative/transitive suffix -す, originally meaning 'to make sufficient' or 'to supplement'.