~切れない
Be unable to finish all of something
You’ll be able to say that an amount or task is too great to complete fully.

空に星が多すぎて、全部は数え切れません。
sora ni hoshi ga oosugite, zenbu wa kazoekiremasen.
What do you think this sentence means?
There are too many stars in the sky; I cannot count them all.
Unable to finish or exhaust something completely
~切れない is the potential negative form of ~切る. It expresses that an amount is so vast that one cannot finish it to the end ("cannot finish eating").
本が多すぎて、一年では読み切れない。
hon ga oosugite, ichinen de wa yomikirenai.
There are too many books; I can't read them all in a year.
大きなピザだったので、二人では食べ切れなかった。
ookina piza datta node, futari de wa tabekirenakatta.
It was a big pizza, so even the two of us couldn't finish it.
Attach 切れない to the masu-stem
Attach 切れない directly to the verb stem (masu-stem). Common combinations include 食べ切れない (cannot eat all), 数え切れない (innumerable), and 使い切れない (cannot spend/use all).
夜空を見上げると、数え切れないほどの星が輝いていた。
yozora o miageru to, kazoekirenai hodo no hoshi ga kagayaite ita.
Looking up at the night sky, countless stars were shining.
~切らない vs ~切れない
~切らない is the plain negative of ~切る: you don’t finish it, often by choice. ~切れない is the potential negative: you can’t finish it, however hard you try.
~切らない, don't finish
今日は全部食べ切らないで、半分残しておこう。
kyou wa zenbu tabekiranaide, hanbun nokoshite okou.
I won't eat it all today; I'll save half.
A choice.
~切れない, can't finish
今日は全部食べ切れないから、半分残しておこう。
kyou wa zenbu tabekirenai kara, hanbun nokoshite okou.
I can't eat it all today, so I'll save half.
Not possible.
買い物をしすぎて、両手でも荷物を持ち切れない。
kaimono o shisugite, ryoute de mo nimotsu o mochikirenai.
I bought too much, so I can’t carry all the bags even with both hands.
この単語帳は言葉が多すぎて、一週間では覚え切れない。
kono tangochou wa kotoba ga oosugite, isshuukan de wa oboekirenai.
This vocabulary book has too many words to memorize them all in one week.
実家から野菜がたくさん送られてきて、二人では使い切れない。
jikka kara yasai ga takusan okurarete kite, futari de wa tsukaikirenai.
My parents sent so many vegetables from home that the two of us can’t use them all up.
7 more examples in the grammar path — free for a limited time.