There seems to be a bit of discrepancy in the lessons, the exercises, and a response to a question in the discussions.
a)First the response in the discussion... where Ainsi que starts the sentence, it seems to make the verb straight forward.
Ainsi que l'italien et l'espagnol, le Français dérive du latin. Very unambiguous that the 'the french' is the singular subject of the verb dériver.
b)The answers to the 'test recommended' provided me.
Les Etats-Unis, ainsi que l'Angleterre, sont un pays anglophone. Here the verb is 'plural BECAUSE the subject is The United States, but the associate nouns and adjectives are singular because it is ONE COUNTRY. Ok so far I think.
c) But in the discussion.
Le français ainsi que l'italien dérivent du latin ( French and Italian) hence a plural verb.
vs
"L'Angleterre, ainsi que la France, a combattu l'Allemagne en 1914." in the lesson.
Shouldn't the verb be 'ont combattu' . And if so maybe a short comment re the gender and plurality of the verb be added to the lesson.