Are you thinking of learning many languages? Do you want to be a polyglot, fluent in dozens of tongues? Planning ahead, what would be an ideal approach to learning dozens of new languages efficiently?
Learning Similar Languages First
In order to learn many languages, it makes sense to learn them in order of similarity. Many languages share a common grammar with neighboring languages and at least a portion of their vocabularies. Learning languages in order of similarity greatly increases the fun factor and reduces stress.