Answer 1

The poet uses some words or phrases in the first stanza to show that the girl working in the field is alone. These words are:
“Single” in the field
“solitary” Highland lass
singing “by herself’
“Alone” she cuts
These words and phrases focus our attention solely on the reaper. We keep our eyes only on her and our ears to her melodious song. These words create a sense of‘mystery’ and the presence of a lonely girl among those natural surroundings does create a romantic setting.