()てにする

あてにする
expression
to count on; to rely on; to expect
1. to count on; to rely on; to depend on; to expect something from someone or something
To place one's expectations or reliance on someone or something. Often used in the negative or with a warning nuance, suggesting that relying on it may lead to disappointment.
(かれ)()てにしないほうがいい。
You'd better not count on him.
ボーナスを()てにして旅行(りょこう)計画(けいかく)した。
I planned a trip counting on my bonus.
天気(てんき)予報(よほう)()てにならないこともある。
Weather forecasts can sometimes be unreliable.
(おや)援助(えんじょ)()てにしていては自立(じりつ)できない。
You can't become independent if you keep relying on your parents' support.

()て means "aim" or "expectation," and ()てにする means to make something one's expectation or reliance. The negative form ()てにならない (unreliable) is extremely common and is one of the most natural ways to say something is unreliable in Japanese.

COMMON PATTERNS:

  • 〜を()てにする: to count on ~
  • ()てにならない: unreliable; can't be counted on
  • ()てにしないほうがいい: you'd better not count on it
  • ()てにしていた: was counting on it

SIMILAR WORDS:

  • (たよ)りにする: to rely on; to depend on — warmer nuance; implies trust and emotional dependence
  • 期待(きたい)する: to expect; to look forward to — more neutral; focuses on anticipation
  • 信用(しんよう)する: to trust — focuses on believing someone is trustworthy