My steam is in Spanish, which makes Spanish the default language after installing FM23, however, I play the game in English (I switched the game from Spanish to English UK through the in-game preferences screen right after installing).
I've had no problems with this before but this year some specific areas of the game remain in Spanish, such as country names, demonyms, player positions/roles, staff roles, names of days of the week and months, injuries, competitions, competition stages, rivalry names, media descriptions (for players), etc.
