she was neither understood by, or herself understood, the cottagers
Although this is an important plot device by which the Creature is allowed to advance in his education, it is more than simply that. What the Creature in his enforced solitude thought of as a "godlike science" (II:4:9) and "the art of language" (II:4:18) is an acquisition essential for his claim to true humanness. As Safie is enfolded by the De Lacey family through acquiring their language, so, the Creature hopes, he can likewise break down the barriers of Otherness in which he is compelled to live. If language has up to now been used as an instrument for his self-knowledge (note), with Safie's arrival it will become the actual means by which he will endeavor to secure a place in a human community.