Subject + 背 + Object / 在…背上
The verb 背 (bēi) means "to carry on the back" and describes the action of supporting something on one's back. As a noun pronounced bèi, it also refers to the back of a person or animal, as in 马背上 (on horseback).
他背着一个大书包去上学。
tā bēi zhe yī gè dà shūbāo qù shàngxué.
He carried a big schoolbag on his back to go to school.
妈妈背着孩子走了很远的路。
māma bēi zhe háizi zǒu le hěn yuǎn de lù.
The mother carried the child on her back and walked a long way.
她背着吉他走进了教室。
tā bēi zhe jítā zǒu jìn le jiàoshì.
She walked into the classroom with a guitar on her back.