Past Tense:
* She dwelt in a small cottage by the sea. (meaning: she lived)
* The author dwelt on the protagonist's childhood trauma. (meaning: focused on)
* The memory of that day dwelt in my mind. (meaning: lingered)
Past Participle:
* The family had dwelt in that house for generations. (meaning: lived)
* He was a man who dwelt in his own world. (meaning: lived in)
* The book dwelt upon the themes of love and loss. (meaning: focused on)
To choose the best usage for "dwelt," consider the context and meaning you want to convey. "Dwelt" can mean "lived," "focused on," or "lingered."