There are some English words that can be partitioned into two strings of letters, say A & B (each part should have more than one letter) in a way that both AB and BA are valid words.
Examples:
Inch>>chin; mode>>demo; upset>>setup & outlook>>lookout. Let’s call them ABBA words.

Compile a list of all 4-letter ABBA pairs of words.
What is the longest ABBA word you have found?
Provide at least one example in another language.

Remarks: all words, including proper names, slang, plurals etc are accepted as long as they can be found in respectable dictionaries. Esoteric words should have proper explanation