When prepositions like shàng, xià, or li are placed, where do they go in relation to the noun (zhëntóu, chuáng)? O before it (shàng chuáng)
0 after it (chuang shàng)
O at the beginning of a sentence (shàng...)
O at the end of a sentence (..shàng)

interesting. Both AB are fine, but the second pinyin of the latter (chuang shang) should be marked with a soft sound, whereas if it is 'xia' there is no need for a soft sound. I don't know if this makes sense to you. if you also have  questions, you can send a message to me.

Explanation:

after it (chuang shàng)

Explanation:

trust