Is it 在桌子上面 or 在桌子的上面?
&quot;的&quot; is a possessive marker like ('s) in English.

&quot;桌子的&quot; = (table's) e.g &quot;桌子的顏色&quot; (the color of the table), in which, the noun &quot;桌子&quot; possess the noun &quot;顏色&quot;

&quot;在 ~ 上面&quot; (on/ on top of/ above) is a preposition. The phrase &quot;在(桌子)上面&quot; (noun + preposition), doesn't require the possessive marker &quot;的&quot; because there is no noun to be possessed.


&quot;在桌子的上面&quot; (on the surface of the table) [preposition + noun + possessive marker + noun] 上面 here is a noun that means  'surface/ top'
&quot;在桌子上面&quot; (on the table) [noun + preposition] 上面 here is a preposition means 'above'
&quot;在桌子上&quot; (on the table) [ noun + preposition]
&quot;在桌上&quot; (on the table) [ noun + preposition]
Example of difference between with or without 的:

書(在)桌子(上面) = the book is (on) the table
書在桌子(的)上面 = the book is on the table('s) surface/top (noun)
In the first sentence, &quot;在 ~ 上面&quot;(on top of) is the preposition; in the second sentence, &quot;在&quot; (on/ at) is the only preposition, while &quot;上面&quot; is a noun that the noun &quot;桌子&quot; possessed

Usage of 的 as an 'adjective marker'

&quot;桌子上的書&quot; (the book on the table)


&quot;桌子上&quot;(on the table) is a noun + preposition

的 here functions as an 'adjective marker' that turns &quot;桌子上&quot; into an 'adjectival phrase': &quot;桌子上的&quot; which describes the noun &quot;書&quot; (the book that's on the table)