how close is Xibe language to Manchu language

Xibe is very close to Manchu—close enough that speakers often get partial mutual intelligibility, especially in vocabulary and grammar, but not always in pronunciation and some newer language changes.

How close they are

• Both are Tungusic languages, and Xibe is commonly described as closely related to written Manchu.

• Many sources characterize Xibe as nearly identical to Manchu in broad structure, with shared script tradition and a lot of overlap in basic grammar and lexicon.

• At the same time, Xibe has developed its own phonology and some morphological differences, so it is not just “the same language”.

Main differences

• Pronunciation: Xibe has shifted in sound system compared with Manchu, so spoken forms can sound noticeably different.

• Vowels and harmony: Xibe is reported to have more vowel distinctions and a more complex vowel harmony system than Manchu.

• Borrowing and contact: Xibe has its own history of contact with surrounding languages, which adds differences from Manchu.

Practical takeaway

If a Manchu speaker and a Xibe speaker had enough exposure to each other, they would likely understand a lot, but not everything. In writing, they may be even closer, since Xibe uses a revised form of the Manchu script.

Plain answer

Think of Xibe and Manchu as near relatives, not twins : very close in core grammar and many words, but with enough sound and usage differences that effortless understanding is not guaranteed.

TL;DR: Xibe is one of the closest living relatives of Manchu, and in some descriptions it is almost mutually intelligible with it, but pronunciation and some grammar/vowel-system differences keep them distinct.