English version

unawares

From Longman Dictionary of Contemporary Englishunawaresun‧a‧wares /ˌʌnəˈweəz $ -ˈwerz/ adverb  1 take/catch somebody unawares2 formalNOTICE without noticing We had walked unawares over the border.
Examples from the Corpus
unawaresTommy and Don stood in the corner, chatting unawares.Perhaps Chapel had proven harder to catch unawares.The thought caught him unawares, and despair filled him.And when it does, as it always does, we are caught unawares and unprepared.But this morning she caught me unawares before I'd had a single cup of coffee.This lad behaved every way as a man would who had happened unawares on murder.