Same & different
Comparing and sorting: the same, another one, weird, normal, all sorts.
onaji
polite onaji desuthe same
同じ おなじ 同じです
Says things are the same (X to onaji) for comparisons on any topic; it goes straight before a noun with no na or no (onaji iro).
onaji iro ga ii
I'd like the same color.
同じ色がいい
onaji iro ga ii desu
I'd like the same color.
同じ色がいいです
watashi mo onaji (same here) is the easy everyday reply.
Learn alongside: betsu
betsu
polite betsu desuseparate, different, another
別 べつ 別です
Means another or a separate one: betsu no X (a different X) and betsubetsu (separately), for choices, payments, plans and people.
betsu no iro ga ii
I'd like a different color.
別の色がいい
betsu no iro ga ii desu
I'd like a different color.
別の色がいいです
Paying separately is betsubetsu de (onegaishimasu). betsu ni (not really) is its own item in C.
hen
polite hen desuweird, strange, odd
変 へん 変です
Says something is strange or off (a taste, a sound, a person, a situation); hen na X goes in front of any noun.
sore, hen da yo
That's weird.
それ、変だよ
sore wa hen desu yo
That's strange.
それは変ですよ
About a person (hen na hito) it is a real criticism; about a taste or a noise it is neutral.
Learn alongside: futsuu
futsuu
polite futsuu desunormal, ordinary, usual
普通 ふつう 普通です
Says something is normal, usual or average and serves as the baseline in comparisons (futsuu wa = usually); futsuu ni means 'normally' and, in casual speech, 'honestly, genuinely' (futsuu ni oishii = it's actually really good).
sore, futsuu da yo
That's totally normal.
それ、普通だよ
sore wa futsuu desu yo
That's quite normal.
それは普通ですよ
As an answer to 'how was it?', futsuu means 'just OK, nothing special'. It is lukewarm, not praise.
Learn alongside: hen
iroiro
polite iroiro desuvarious, all sorts
いろいろ いろいろです
Means many different things without listing them: iroiro na X (all sorts of X), iroiro atta (a lot happened), iroiro arigatou (thanks for everything).
kyou wa iroiro atta
A lot happened today.
今日はいろいろあった
kyou wa iroiro arimashita
A lot happened today.
今日はいろいろありました
As a reply, iroiro desu ne means 'it varies, it depends'.
Learn first: aru