You can change the language in YoungCRM. Note that language is defined on two levels: the organisation's language and the user's individual language.
The organisation's language is used to communicate with people who register in the system. This means all default messages and information.
The user's language is what the individual user will be shown in YoungCRM. That is menus, settings, etc.
Therefore, the organisation and user language can differ. The organisation's language is what is shown externally to people, while the user's language is what the individual is shown internally in the system.
Change organisation language
In order to change the organisation's language, start by clicking the organisation's name in the top right corner and go to 'Organisation settings'.
Afterwards, go to 'System settings', which can be found to the left, and select the language you would like to set as the default organisation language. Remember to click 'Save changes'.
Change user language
In order to change your user language, start by clicking the organisation's name in the top right corner and go to 'My profile'. Select the desired language and click 'Save changes'.
Here's a video on how to change language.