Meaning of ちがいない in Japanese

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Definition of ちがいない

ちがいない(chigainai) 【違いない ·違い無い】

にちがいない(nichigainai) 【に違いない】

まちがいない(machigainai) 【間違いない ·間違い無い】

(exp, adj-i) certain; sure; doubtless →Related words: 紛れもない
それは間違いなく空飛ぶ円盤だったのだ。
It was a flying saucer all right.
(exp) I have no doubt; You can depend on it; It's a safe bet

She must have been very young when she wrote this poem.

It must have been difficult for her to knit this sweater.

It follows from this that he must be innocent.

あの老人ろうじんは頭がおかしいあたまがおかしいにちがいない。

That old man must be off his rock.

あの人達ひとたちは私わたしが盗みぬすみをしたすると疑ったにちがいない。

They must have suspected me of stealing.

あの人ひとはトムの兄弟にちがいない。

He must be Tom's brother.

They must have been overcome by the recent disasters.

あの紳士しんしは医師いしにちがいない。

That gentleman must be a doctor.

You must have been surprised to find me alone with her last night.

You must be worn out after working all day.