I think it is easy, but I speak only european languages. Not sure if it is really easier or I just feel that is easy because I know the languages I do.

I would love to say mandarin/chinese, but tonal languages scares me.

I made a grammar rule set (not a complete conlang yet) where verbs don’t need to be conjugated, and information about time is separated from the verb; A new lingua franca, IMHO, should not have verb conjugation.