〜すぎる: go beyond a suitable degree
Express too much of an action or quality. Learn the connecting forms and distinguish excess from simply very.
Attach it to verbs and adjectives
Use a verb’s masu-stem for 食べすぎる or 働きすぎる. Remove final い from an i-adjective to make 高すぎる or 暑すぎる.
Na-adjectives connect without な: 静かすぎる and 便利すぎる. Conjugate the final すぎる for forms such as 高すぎました and 食べすぎない.
A high degree is not always an excessive degree
この机はとても大きいです。 says the desk is very large. この部屋には大きすぎます。 judges it too large for this room.
すぎる presents a degree beyond what suits a purpose or standard. Find that standard in context instead of replacing every とても with すぎる.
Identify what is being evaluated
昨日、歩きすぎました。 evaluates yesterday’s amount of walking as excessive. 道が長すぎました。 instead evaluates the length of the road.
すぎる does more than intensify a word; it judges the degree as beyond what suits the context. In この荷物は重すぎて、一人では持てません, the luggage is too heavy for one person to carry.
Quick check: Does 静か become 静かなすぎる or 静かすぎる?
Show the answer and why
静かすぎる. Do not insert な after the na-adjective. The polite past is 静かすぎました.