You can use “boring” or “bored” in daily conversation particularly under a coronavirus crisis although they have negative meanings. I will introduce how you can translate them, when you can say them and their nuances.
You can translate both of “bored” and “boring” into “taikutsu”/「退屈」in Japanese. Japanese people very often say it in daily conversation. This word is neither casual or formal, so you can say it to someone whom you don’t know very well or elderly people. Even if you do that, they wouldn’t feel you are impolite. I will introduce the examples.
I’m so bored because I can’t go to restaurants under the lockdown./ロックダウンでレストランに行くことができないので、とても退屈です。
Ex) At a bar
A:Am I boring you ?/退屈させてる？
B:No, not at all./全然そんなことないよ。
You can translate only “boring” into “tsumaranai”/「つまらない」in Japanese, but it’s unnatural if you translate “bored” into “tsumaranai”/「つまらない」. I mean Japanese people don’t say “tsumaranai”/「つまらない」as the meaning of “bored”. “tsumaranai”/「つまらない」is a little casual expression and “tsumannai”/「つまんない」impresses people more casual. I will introduce the example.
This video game was very boring./このゲームはとてもつまらなかった。
Even if you say 「私はつまらない」, that means “I’m boring” in English.
You can translate both of “bored” and “boring” into “unzari”/「うんざり」in Japanese. Japanese people often say it in daily life. You can express your feelings more strongly than “taikutsu”/「退屈」. I think it’s not common that you say it in a business situation. I will introduce the example.
His story is boring./彼の話はうんざりだ。
I’m bored with waiting for a long time./長い時間待って、うんざりだ。
You can translate both of “bored” and “boring” into “taikutsu”/「退屈」or “unzari”/「うんざり」. “boring” can be translated into “tsumaranai”/「つまらない」, but “bored” isn’t. “tsumaranai”/「つまらない」is a little casual expression and “tsumannai”/「つまんない」is very casual. You can express your feelings more strongly with “unzari”/「うんざり」.