意志(いし)

意志(いし) refers to a person's will, determination, or resolve — the inner drive to act or achieve something. It emphasizes firmness of purpose.

COMMON COLLOCATIONS:

• 意志(いし)が強(つよ)い: strong-willed
• 意志(いし)が弱(よわ)い: weak-willed
• 意志(いし)を持(も)つ: to have a will/determination
• 自分(じぶん)の意志(いし)で: of one's own will
• 意志(いし)を貫(つらぬ)く: to carry through one's will
• 意志(いし)表示(ひょうじ): declaration of intent

KANJI DISTINCTION:

• 意志(いし) (志(こころざし)): will, volition — emphasizes determination and resolve
• 意思(いし) (思(おも)い): intention, mind — emphasizes what one thinks or intends
• Example: 意志(いし)が強(つよ)い (strong-willed) vs. 意思(いし)表示(ひょうじ) (expression of intent)

In practice, 意志(いし) focuses on firmness and character, while 意思(いし) focuses on one's wishes or intentions in a specific situation.