What are two phases during which the moon appears as only tiny sliver?

The two phases during which the moon appears as only a tiny sliver are the waxing crescent and the waning crescent phases. In the waxing crescent phase, the moon is transitioning from new moon to first quarter, gradually becoming more illuminated. Conversely, in the waning crescent phase, it is moving from the last quarter back to the new moon, with only a small portion of the moon's surface visible. During both phases, the illuminated part of the moon appears as a thin crescent shape.