Would I just use わるい? Or is there a more specific word for being unskilled at something?
私の日本語は悪いです。< Would something like this suffice?
You have several ways to say "I'm bad at Japanese". The most common (and direct) ways to say it would be:
- 私は日本語が[下手]{へた}です。(lit. As for me, Japanese is poor.)
- 私の日本語は下手です。(lit. My Japanese is poor.)
悪い is a literal translation of the English "bad". In Japanese, you don't use 悪い to say you're bad/unskillful at something.
You could also express it as "I'm not good at Japanese":
- 私は日本語が[上手]{じょうず}ではありません。(lit. As for me, Japanese is not good/skillful.)
- 私は日本語が[上手]{うま}くありません。(lit. As for me, Japanese is not good.)
Depending on what you're bad at, you could also use [苦手]{にがて}, which is closer to "weak":
- 私は[料理]{りょうり}が苦手です。(≂ 私は料理が下手です。)
I'm bad at cooking.- 私は[泳]{およ}ぎが(or[水泳]{すいえい}が)苦手です。(≂ 私は泳ぎが/水泳が下手です。)
I'm bad at swimming.- 私は数学が苦手です。(but not 私は数学が下手です。)
I'm weak at maths.- 私は英語が苦手です。(When talking about English as a school subject, use 苦手. You don't use 下手 for school subjects.)
I'm weak at English.
This time you can rephrase them as "not good/strong at~~" using [得意]{とくい}:
- 私は料理が得意ではありません。
I'm not good at cooking.- 私は数学が得意ではありません。(but not 私は数学が上手ではありません。)
I'm not strong at maths.
Well, you could just use 下手{へた} that is basically the opposite of 上手.
So basically you could say 私は日本語が下手です。
To add one more you could probably use 苦手{にがて} as well, which means "poor (at something), weak, unskilled" etc. So you would say 私は日本語が苦手です。
I think the most natural would be
私は日本語があまり上手じゃありません。
lit. My japanese is really not very good.
Actually 下手 (the kanji opposite of 上手) is a common way of saying you are not very good at something.
私の日本語は下手です。
Alc reference here:
My teacher told me using 上手 with yourself sounds pretty bad. There was another expression but I can't find it anywhere.