zhè bǎ yǐzi fàng zài zhuōzi zuǒbian, nà bǎ yǐzi fàng zài yòubian.

Here 把 is a measure word (classifier) for things with a handle or things you can grab, including 椅子 (chairs), 扇子 (fans), 刀 (knives), etc.

Structure:

• 这 + 把 + 椅子 = this chair
• 那 + 把 + 椅子 = that chair

It is not the 把-disposal construction.

The 把-construction looks like:

• 把 + object + verb + other elements
  e.g. 把书放在桌子上 – put the book on the table.

In your sentence, 把 comes between a demonstrative (这 / 那) and a noun (椅子), which is exactly where a measure word goes. So:

• 这把椅子 = demonstrative + classifier + noun
• Not: 把椅子放在… (disposal).

In standard Mandarin, when you use 这 (this) or 那 (that) with a countable noun, you almost always need a measure word in between:

• 这 + (measure word) + noun
• 那 + (measure word) + noun

So for 椅子 the usual classifier is 把:

• 这把椅子 – this chair
• 那把椅子 – that chair

Saying 这椅子 / 那椅子 without a classifier sounds incomplete or non-standard in most contexts, although you might occasionally hear it in very casual speech.

So: the measure word is grammatically required here.

放 means to put / place.
在 is a preposition meaning at / in / on, and in this pattern it marks a location.

The key pattern is:

• 把/subject + object + 放在 + location
• or without 把: object + 放在 + location

Examples:

• 把椅子放在桌子左边 – put the chair on the left side of the table
• 椅子放在桌子左边 – the chair is (placed) on the left side of the table / put the chair…

Saying 放桌子左边 without 在 is ungrammatical in standard Mandarin.
With verbs of placing (放, 放下, 摆, 贴, 挂, etc.), you almost always need 在 before the location phrase.

So 放在 + place is the normal pattern.

The sentence is:

这把椅子放在桌子左边，那把椅子放在右边。

Think of it as two parallel clauses:

1. 这把椅子 / 放在 / 桌子左边
2. 那把椅子 / 放在 / 右边

Basic pattern:

• subject (or topic) + verb + 在 + location

Rough comparison to English:

• Chinese: This chair put-at table left-side, that chair put-at right-side.
• English: Put this chair to the left of the table, and put that chair to the right.

So the location comes after the verb via 在 + place, instead of using an English preposition like to the left of before the noun.

This is ellipsis (leaving out repeated information).

• First part: 桌子左边 – the left side of the table
• Second part: 右边 – literally just “the right side,” but from context it clearly means the right side of the same table.

In natural Chinese (and English), when the reference is obvious and just mentioned, you don’t repeat it:

• English: “Put this chair on the left of the table, and that one on the right.”
  (We don’t say “on the right of the table” again.)

Chinese does exactly the same here. A fully explicit version could be:

• 这把椅子放在桌子左边，那把椅子放在桌子右边。

But that’s a bit heavier; the shorter version is more natural.

Both are possible:

• 桌子左边
• 桌子的左边

They mean essentially the same: “the left side of the table.”

Usage nuance:

• When the relationship is very close and obvious (like object + its side/top/inside), 的 is often dropped:

  • 桌子左边 – left side of the table
  • 门外面 – outside the door
  • 书里边 – inside the book

• Including 的 (桌子的左边) can sound a bit more explicit or emphatic, but not necessarily more “correct.” It’s fine, just slightly heavier.

So in everyday speech, 桌子左边 (without 的) is very natural and common.

They’re all related to left / side, but not identical:

• 左边 (zuǒbian)

  • Very common for “the left (side)”.
  • Works well for locations: 在桌子左边 – on the left side of the table.

• 左面 (zuǒmiàn)

  • Similar meaning to 左边, also “the left side.”
  • Often interchangeable with 左边 in everyday speech.

• 旁边 (pángbian)

  • Means “beside / next to / by the side of” without specifying left or right.
  • 在桌子旁边 – next to the table (could be left or right).

• 左 (zuǒ) on its own

  • Basic direction word “left”.
  • Used in combinations like 左边, 左手 (“left hand”), 左转 (“turn left”).
  • On its own as a place word (在桌子左) is not natural; you normally say 左边 or 左面.

In your sentence, 左边 / 右边 is the most natural and common choice.

的 is used when the phrase modifies a noun that comes after it.

• 左边的椅子 – the chair on the left side
• 右边的那个人 – that person on the right

In your sentence, 左边 and 右边 themselves are the location nouns, not modifiers:

• 放在桌子左边
  → the chair is put at the left side of the table
  (Here 左边 is the place, so no noun after it.)

If you add 的, you’d need a noun after it:

• 放在桌子左边的地方 – put it in the place that is on the left of the table.
• 左边的椅子放在桌子旁边 – the chair on the left is placed next to the table.

So in 在桌子左边 / 在右边, 左边 / 右边 stand as full location nouns, and 的 is not needed.

The Chinese sentence can mean either depending on context and tone:

• Imperative (command/instruction):
  (你) 把这把椅子放在桌子左边，那把椅子放在右边。
  → “You put this chair on the left side of the table, and that chair on the right.”

• Descriptive (stating a fact):
  这把椅子放在桌子左边，那把椅子放在右边。
  → “This chair is placed on the left side of the table, that chair is placed on the right.”

In writing, with no context, both readings are possible.
In real life:

• Said with an instructing tone, it’s understood as a command.
• Said in a neutral, descriptive tone, it’s understood as a description.

Chinese often leaves out the subject like 你 (“you”), relying on context to show whether it’s an order or a statement.

Two different patterns:

1. Subject + 在 + place (using 是 optionally for emphasis)

   • 椅子在桌子左边。 – The chair is on the left of the table.
   • 椅子是在桌子左边。 – The chair is on the left of the table (emphasizing the location).

2. Subject + 放在 + place

   • 椅子放在桌子左边。
     
     • Either: the chair is placed on the left
     • Or: (you should) put the chair on the left.

In your sentence, 放 is the main verb, so you don’t use 是.
Using 是 here would make it sound like you are equating the chair with a location, which doesn’t fit the verb 放.

So:

• 椅子在桌子左边 → focuses on location/state
• 椅子放在桌子左边 → focuses on the action or result of placing

Dictionary tones:

• 椅 (yǐ) – 3rd tone
• 子 (zi) – 3rd tone

But in real speech:

• 椅子 is pronounced yǐ·zi:
  
  • 椅 (yǐ): full 3rd tone
  • 子 (zi): neutral tone (light, short, no strong pitch contour)

This happens because 子 is often a suffix in nouns (桌子, 椅子, 帽子, 盒子, etc.), and in that position it typically becomes neutral tone.

So you should say yǐ·zi, not two full third tones.

Historically, 子 can mean “child,” but in words like 桌子 and 椅子, it’s mostly a noun-forming suffix and doesn’t carry a concrete meaning by itself.

Examples:

• 桌 + 子 → 桌子 – table
• 椅 + 子 → 椅子 – chair
• 帽 + 子 → 帽子 – hat
• 盒 + 子 → 盒子 – box

You cannot usually take away 子 and use the remaining part (桌, 椅) as a normal standalone noun in modern spoken Chinese. So here, 子 is just part of the fixed word and is best learned together with the whole noun.

The standard classifier for 椅子 is 把:

• 一把椅子, 这把椅子, 那把椅子

Using 张 (一张椅子) is not standard. 张 is used for flat objects like paper, tables, beds:

• 一张桌子 – one table
• 一张床 – one bed
• 一张纸 – one sheet of paper

For chairs, learners should stick to 把.

So:

• ✓ 这把椅子 – correct
• ✗ 这张椅子 – sounds wrong to native speakers.

Yes, you can:

1. (你) 把椅子放在桌子左边。

   • Imperative: “Put the chair on the left side of the table.”
   • 把 here is now the disposal marker, not a classifier.
   • 椅子 is general: the chair / chairs understood from context.

2. 椅子放在桌子左边。

   • Either description: “The chair is placed on the left side of the table.”
   • Or instruction, depending on tone: “(You) put the chair…”

When you keep 这 / 那:

• 这把椅子 – specifically this particular chair
• 那把椅子 – specifically that particular chair

So:

• With 这 / 那 → you’re distinguishing this one vs that one.
• Without them → just talking about the chair(s) the listener knows about from context.