Price & speed
The two everyday scales for errands and plans: what something costs and how early, late, fast or slow it is.
takai
polite takai desuexpensive, high, tall
高い たかい 高いです
Expensive (the daily shopping sense), and also high or tall for buildings, people, voices and levels; the opposite is yasui for price and hikui for height.
kono mise, takai ne
This place is expensive.
この店、高いね
kono omise, takai desu ne
This place is expensive.
このお店、高いですね
se ga takai = tall (of a person).
Learn alongside: yasui
yasui
polite yasui desucheap, inexpensive
安い やすい 安いです
Says something is cheap or good value (prices, shops, deals); it is the opposite of takai only in the price sense.
kono mise, yasui ne
This place is cheap.
この店、安いね
kono omise, yasui desu ne
This place is cheap.
このお店、安いですね
It is a different word from the suffix -yasui (easy to ...): tabeyasui = easy to eat.
hayai
polite hayai desuearly, fast, quick
早い はやい 早いです
Early in time ('mou? hayai!') and fast in speed or progress; it is one word by ear but has two kanji in writing (早い early, 速い fast).
kyou, hayai ne
You're early today.
今日、早いね
kyou wa hayai desu ne
You're early today.
今日は早いですね
The adverb hayaku (quickly, early) is its own item in C.
Learn alongside: osoi
osoi
polite osoi desulate, slow
遅い おそい 遅いです
Late in time or slow in speed; 'mou osoi' means it's too late now, and 'osoi!' is the complaint to someone who kept you waiting.
kyou, osoi ne
You're late today.
今日、遅いね
kyou wa osoi desu ne
You're late today.
今日は遅いですね
'Late for something' uses the verb okureru (densha ni okureta), not osoi.