wǒ chūmén qián wàng le guān dēng.

I

Breakdown of wǒ chūmén qián wàng le guān dēng.

• 了le: perfective particle
• 灯dēng: light

Questions & Answers about wǒ chūmén qián wàng le guān dēng.

Why is 前 placed after 出门 in 出门前?

Because Chinese often forms before/after doing something expressions as:

verb phrase + 前 / 后

So:

• 出门前 = before going out
• 吃饭前 = before eating
• 睡觉前 = before sleeping

In other words, 前 means before, but it comes after the action it refers to.

So 我出门前忘了关灯 literally follows the pattern:

I + before going out + forgot + turn off the light

That is normal Chinese word order.

Why is 出门前 placed before 忘了关灯?

Chinese usually puts time expressions before the main action.

A very common pattern is:

subject + time expression + verb phrase

So here:

• 我 = subject
• 出门前 = time expression
• 忘了关灯 = main event

This is why the sentence is arranged as:

我 出门前 忘了 关灯

That word order is much more natural in Chinese than putting the time phrase later.

What does 了 mean in 忘了?