Bienvenu/Bienvenue les enfants!
Duolingo offers these two translation options for the sentence "Welcome children!". Am I right in assuming that the choice between "bienvenu" and "bienvenue" depends on the sex of the speaker? Thank you!
As there is no verb used during the welcoming of the children, the correct form is bienvenue (fem). It is just a rule.
It's only when you use a complete sentence that you can say something like Soyez le bienvenu or Soyez la bienvenue, according to the gender of the person you are talking to, or Soyez les bienvenus if it's more than one person.