different ways to show the existence of an object

 Here is a summary of different ways to show the existence of an object:

to show the existence of an object: Place + 有（you) + object  note:  place = 在 + Location+ 上 / 下 / 里 / 旁边/中间)	宿舍里 有 一张床。 There is a bed in the dorm.
to identify the object in certain place: Place + 是(shi) + object	柜子上 是 一个灯。 It is a lamp on the closet.
to emphasize how the things exist: Place + verb-着+ object verbs: 放 fang4 to put 摆 bai3 to display 挂 gua4 to hang	柜子 上 放着 一个灯。 There is a lamp put on the closet. 柜子(gui zi) 上 摆着(bai zhe) 一个灯(deng)。 There is a lamp displayed on the closet. 墙上（qiang2 shang4)  挂着(gua4 zhe) 两个帽子（mao zi )。 There are two hats hanging on the wall.
to show the location of the objects: Something + 在(zai) + Place	书包 在 地毯（di4 tan3)上。 The bag is on the carpet

有 vs. V着

More examples: 

手里有一杯茶                 手里拿着一杯茶

桌子上有一本书                    桌子上放着一本书

教室里有二十个学生            教室里坐着二十个学生

教室里有一位老师                教室里站着一位老师

衣架上有一件大衣                衣架上挂着一件大衣

墙上有一张照片                    墙上贴着一张照片

黑板上有一个字                    黑板上写着一个字

Questions: How to say these 4 sentennces in Mandarin 

1. There is a chair in front of the table.(Place + 有 + object ) 

2. There is a jacket hanging on the chair. (Place + verb-着+ object)

3. The blanket is on the bed.(Something + 在 + Place) 

4. It is a backpack on the carpet. (Place + 是 + object)

note: place = 在 + Location+ 上边 / 下边 / 左边/右边/前边/后边/ 里边 / 旁边/中间)