例文１「彼は仕事が遅い。」
work slow を使って言うことができます。
He is a slow worker. とも言えます。
例文２「彼はもたもた仕事をする。」
仕事が遅い人は非効率的な人が多いと思うので、このようにも言えるかなと思います。
inefficiently で「非効率的・もたもた」
ご参考になれば幸いです！
"His work is inefficient" If someone works slow they are inefficient, they can't finish their tasks on time or their work lacks quality.
"He's not very productive" If someone is productive they are working at a good pace and getting many things done. If someone isn't productive that means they aren't completing many tasks due to being slow or slacking off.
"His work is inefficient"（彼の仕事は無駄が多い）
仕事が遅い人のことは "inefficient" と言えます。仕事を予定通りに終わらせることができなかったり、仕事のクオリティーが低い人を言います。
"He's not very productive"（彼は仕事が遅い）
"productive" はスピーディーに多くの仕事をこなせる人を言います。
反対に、"not productive" は、のろかったり怠けていたりで仕事があまりできない人を言います。
❶Works at a slow pace. (遅い/ゆっくりなペースで仕事をする)。
She works at a slow pace. Should I tell her to work faster?
(彼女はゆっくりなペースで仕事をする。もっとはやく働いて、て言ったほうがいいかな？)
❷ slow worker パパッと働けない人/ゆっくり働く人 のことです。
Why am I such a slow worker?
(なんで私ってこんなに働くのが遅いんだろ？)
He’s a slow worker, (彼はゆっくり働く人だ)。
参考に。
He is a slow worker. - a way to explain the pace a person works at.
He works at a snails pace. - this is more of a common phase in English, as snails are super slow and thus people are often compared to them.
He is a slow worker.（彼は仕事が遅い）
- 人の仕事をするペースについて伝える言い方です。
He works at a snails pace.（彼は仕事が遅い）
- これはより一般的なフレーズです。"snails"（カタツムリ）は動きがすごく遅いですが、人もこれによくたとえられます。
'He's a slow worker'; means that the person works very slow. It takes him a while to finish one task before moving on to the next one.
'He doesn't work efficiently.' means; that he does not work in a way that is very productive and at the same time uses minimum effort and wastes no time. In actual fact this person is unproductive because he chooses to waste time and effort doing things that do not necessarily need to be done.
A slowcoach is an informal description for someone who is slow at working and moving. They do everything slowly and lack speed, therefore they are referred to as a slow coach.
If you say that someone is slow or that they work slowly, it can be a little offensive. By talking about task completion, it's a indirect and can allow you to talk about his abilities in a professional way. I hope that this helps. :)
The word that most closely follows your sentiment is "efficiency". This refers to how fast someone or something is accomplishing something. For instance if I am able to answer 20 questions per hour, but another tutor answers 30 per hour. They are more "efficient" than I am.
Efficient - achieving maximum productivity with minimum wasted effort or expense.
Alternates:
He is slow.
He works slow.
He is not fast enough.
He is not efficient.
あなたの気持ちに最も近い言葉は "efficiency" です。これは仕事をこなす速度を表します。例えば、私は1時間に20個の質問に答えることができます。別の講師は1時間に30個の質問に答えることができます。この場合、その講師は私よりも "efficient" です。
Efficient - 最少の労力・出費で最大の生産性を得ること。
他の言い方：
He is slow.
He works slow.
He is not fast enough.
He is not efficient.
（彼は仕事が遅い）
You would like to explain that someone works slowly. In that case, you can try one of the above-suggested example sentences which may be appropriate for any given situation. There are always a variety of ways to respond to someone or make a comment - depending on the context and other factors such as nationality, appropriacy and body language
Here are two sentences that can be used interchangeably to have the same meaning. One uses the verb version of the word, "work," whereas the other uses the noun version of, "worker," with the adjective, "slow," modifying the noun.
日本 
カナダ 
アメリカ合衆国 
南アフリカ 
イギリス 
