principal 可作名詞或形容詞，而principle 只能做名詞。
principal ["prɪnsəp(ə)l] 本金，委託人，資本，主角 ，最重要的，主要的。principle ["prɪnsəp(ə)l] 原理，原則，工作原理，法則。
雙語例句:
The principal reason for my change of mind is this.
這是我改變主意的最主要原因。
Donald King is the principal of Dartmouth High School.
唐納德·金是達特茅斯中學的校長。
Their principal concern is bound to be that of winning the next general election.
他們最關心的問題肯定是贏得下一次大選。
The students passed a motion of no-confidence in the college principal.
學生們通過了對校長進行不信任投票的動議。
Buck never allowed himself to be bullied into doing anything that went against his principles
巴克從來不會因為受到威脅而做違背自己原則的事情。
The doctrine was based on three fundamental principles.
這個學說建立在三條基本原理之上。
These people lack all understanding of scientific principles.
這些人對科學原理一竅不通。
I agree with it in principle but I doubt if it will happen in practice.
我大體上同意這一點，但是懷疑它是否能夠付諸實踐。
principal 可作名詞或形容詞，而principle 只能做名詞。
principal ["prɪnsəp(ə)l] 本金，委託人，資本，主角 ，最重要的，主要的。principle ["prɪnsəp(ə)l] 原理，原則，工作原理，法則。
雙語例句:
The principal reason for my change of mind is this.
這是我改變主意的最主要原因。
Donald King is the principal of Dartmouth High School.
唐納德·金是達特茅斯中學的校長。
Their principal concern is bound to be that of winning the next general election.
他們最關心的問題肯定是贏得下一次大選。
The students passed a motion of no-confidence in the college principal.
學生們通過了對校長進行不信任投票的動議。
Buck never allowed himself to be bullied into doing anything that went against his principles
巴克從來不會因為受到威脅而做違背自己原則的事情。
The doctrine was based on three fundamental principles.
這個學說建立在三條基本原理之上。
These people lack all understanding of scientific principles.
這些人對科學原理一竅不通。
I agree with it in principle but I doubt if it will happen in practice.
我大體上同意這一點，但是懷疑它是否能夠付諸實踐。