chāixiāng yǐhòu ānzhuāng shūjià.

The pattern is:

Verb phrase + 以后 + Verb phrase

So here:

• 拆箱 = unbox / unpack
• 以后 = after
• 安装书架 = install / assemble the bookshelf

So the whole sentence means After unboxing, assemble the bookshelf.

This is a very common way in Mandarin to show that one action happens after another.

Mandarin often leaves out the subject when it is obvious from context.

In a sentence like this, especially in instructions, manuals, or step-by-step directions, the understood subject is usually:

• you
• or a general instruction like one should

So 拆箱以后安装书架 sounds natural as an instruction. In English, we often also omit the subject in commands, as in Open the box. Then assemble the shelf.

Here, 以后 means after.

When it comes after a verb phrase, it means after doing something:

• 吃饭以后 = after eating
• 下班以后 = after getting off work
• 拆箱以后 = after unboxing

A useful thing to remember is that 以后 can also mean later or in the future in other contexts, but in this sentence it clearly means after.

拆箱 is made of:

• 拆 = take apart, open up, undo
• 箱 = box

Together, 拆箱 means opening the box and taking the contents out, so unbox or unpack both fit.

In product instructions, 拆箱 is very common. A longer, more literal way to say this would be something like:

• 打开箱子以后 = after opening the box

But 拆箱 is shorter and sounds more like the wording you see in manuals.

This is a very good question, because both verbs can appear in similar contexts.

• 安装 usually means install, set up, or fit into place
• 组装 usually means assemble from parts

For furniture like a bookshelf, 组装 is often very natural if you want to emphasize putting pieces together.

However, 安装书架 is also common, especially in instruction-style language. It can sound a little more formal or manual-like. In many real situations, both are possible, depending on what exactly you mean:

• 组装书架 = assemble the bookshelf from parts
• 安装书架 = install / set up the bookshelf

So the sentence is natural, even if some speakers might also expect 组装 in a furniture context.

Because 以后 already shows the sequence clearly: first unbox, then assemble.

In instruction-style Mandarin, you often do not need 了. The sentence is simply stating the order of actions.

So:

• 拆箱以后安装书架 = after unboxing, assemble the bookshelf

You might sometimes hear or see:

• 拆箱以后，再安装书架
• 拆箱了以后，再安装书架

But the version without 了 is concise and very natural in instructions.

No. 以后 can come after both verb phrases and time expressions.

Examples:

• 吃饭以后 = after eating
• 下课以后 = after class
• 三点以后 = after three o’clock
• 明天以后 = after tomorrow

In your sentence, 以后 follows a verb phrase, 拆箱, so it means after unboxing.

Not necessarily. 以后 mainly shows sequence, not immediacy.

So the sentence means:

• first unbox
• then assemble the bookshelf

But it does not by itself say immediately.

If you wanted to make the order even more explicit, you could say:

• 先拆箱，再安装书架。 = First unbox it, then assemble the bookshelf.

If you wanted to emphasize doing it right away, you could add something like:

• 拆箱以后马上安装书架。 = After unboxing, immediately assemble the bookshelf.

Mandarin does not use articles like a or the the way English does.

So 书架 can simply mean:

• a bookshelf
• the bookshelf

The exact meaning depends on context.

Also, measure words such as 一个 are usually not needed when the noun is a direct object in a straightforward instruction.

So:

• 安装书架 = assemble/install the bookshelf

If you wanted to be more specific, you could say:

• 安装这个书架 = assemble this bookshelf
• 安装一个书架 = assemble a bookshelf

But the shorter form is perfectly normal.

Yes, in context it most likely functions as a command or instruction.

Even though there is no special command form here, Mandarin often uses a plain verb phrase to give instructions, especially in manuals, signs, and procedural steps.

So 拆箱以后安装书架 is understood as:

• After unboxing, assemble the bookshelf

It is not necessarily rude; it is just concise instructional language.

The pronunciation is:

• 拆箱 — chāixiāng
• 以后 — yǐhòu
• 安装 — ānzhuāng
• 书架 — shūjià

Tone breakdown:

• 拆 chāi — first tone
• 箱 xiāng — first tone
• 以 yǐ — third tone
• 后 hòu — fourth tone
• 安 ān — first tone
• 装 zhuāng — first tone
• 书 shū — first tone
• 架 jià — fourth tone

A natural rhythm would be:

chāixiāng yǐhòu / ānzhuāng shūjià

with a small pause after 以后.