普通形とです・ます、どっち？ (futsuukei to desu-masu, docchi?) — Who gets which

Where the line falls at work — who gets casual speech and who gets です／ます.

Formula (सूत्र ढाँचा)

店長・課長・お客さん → です・ます

先輩 → です・ます

同僚・友達 → 普通形

迷ったら → です・ます

Always です／ます: your 店長, 課長, 部長, any 先輩, customers, and anyone you met today.
Plain form is fine: friends, 同僚 of your own age and rank, and 後輩 who joined after you — but only once they have used plain form with you first.

Three rules to remember.
One: let the other person switch to plain form first, then match them; do not start it yourself.
Two: even when a 先輩 says 「休み？」to you, you answer 「はい、休みです」— it runs one way only, and this is the part most Nepali workers get wrong.
Three: in Japan a 先輩 is made by joining date, not age — someone two years younger than you is still your 先輩 if they started first.
When in doubt, です／ます: nobody is ever offended by polite speech, while plain form in the wrong place sounds rude.

The かい, じゃないか, かな and さすが in this lesson are for understanding, not for speaking — but 〜てよかったです and 〜てすみません you can use with anyone, starting today.

先輩に「お疲れさまです」。

せんぱいに「おつかれさまです」。

To a 先輩: 「お疲れさまです」.

同僚に「お疲れ」。

どうりょうに「おつかれ」。

To a same-age 同僚: 「お疲れ」.

店長が「今日忙しい？」と聞いても、「はい、忙しいです」。

てんちょうが「きょういそがしい？」ときいても、「はい、いそがしいです」。

Even when the 店長 asks 「今日忙しい？」, you answer 「はい、忙しいです」.

Question: 1/3

Someone is two years younger than you but joined the company a year before you. How do you ask them "Heading home already?"

💡 Hint: It is not about age — it is about who joined first.