Learn Hardcore Chinese: wǒ zuò zhe děng tā. - I am sitting and waiting for her.

着 after a verb marks a continuing state (durative aspect).
In 我坐着等她, 着 is on 坐, so it means “being in a sitting state.”
The main action is 等 “to wait.” Structure: V1 + 着 + V2 = do V2 while in the state/result of V1.

Why isn’t 在/正在 used to mark the progressive?

Chinese doesn’t have to mark the progressive every time. Here, 坐着 gives the background state, and the context implies the ongoing action of 等. If you want to highlight the progressive, you can say:

我在等她 or 我在等她呢 (I’m waiting for her)
You can also keep the posture: 我坐着等她呢 (I’m sitting, waiting for her).

Is “我坐着在等她” or “我在坐着等她” okay?

我坐着等她: most natural and concise.
我坐着在等她: acceptable; adds explicit progressive on 等; a bit wordier.
我在坐着等她: grammatical but uncommon/heavy in everyday speech; people usually avoid it.
Note: 坐在… must take a place: e.g., 我坐在咖啡馆等她 (I sit at the café and wait for her).

Should there be a comma: “我坐着，等她”?

No. It’s one predicate chain (posture + main action). A comma would wrongly split them into separate coordinated actions.

Can I drop 着 and say “我坐等她”?

Generally no in modern colloquial Chinese. 坐等 exists as a set/Internet-y phrase (e.g., 坐等好消息 “sit and wait for good news”), but for normal speech, use:

我坐着等她 (while sitting)
or add a place: 我坐在这儿等她.

Can I put 着 on 等 as well: “我坐着等着她”?

Yes. 我坐着等她 and 我坐着等着她 are both acceptable. 等着 emphasizes the ongoing nature of the waiting a bit more. In everyday speech, one 着 is usually enough.

How do I add duration, like “I waited for her for an hour” or “I’ve been waiting for an hour”?

Completed past: 我坐着等了她一个小时。
Still ongoing now: 我坐着等了她一个小时了。 / 我坐着等她等了一个小时了。 (着 stays on 坐; 了 marks the action 等 and/or the sentence for ongoing duration.)

How do I negate this?

Negate the state/action as a fact: 我没坐着等她。 (I wasn’t sitting waiting for her.)
Refuse/habitual negation: 我不等她。 (I won’t/don’t wait for her.)
Imperative: 别坐着等她。 (Don’t sit and wait for her.)

Where do I put the place?

Two common options:

我在咖啡馆坐着等她。 (At the café, I sit and wait for her.)
我坐在咖啡馆等她。 (I sit at the café and wait for her.) Both are fine. With 坐在, you must supply a location.

What’s the difference between 等她, 等她来, and 等她到?

等她: wait for her (general).
等她来: wait for her to come.
等她到: wait for her to arrive (reach here).
“Wait until she arrives” can also be 等到她来/到.

Can I say “我等她坐着”?

That reads as “I wait for her to sit (down).” If that’s what you mean, say 我等她坐下. For “I wait for her while sitting,” keep the original order: 我坐着等她.

How is 着 pronounced here, and how does it differ from other readings?

Aspect particle: zhe (neutral tone), e.g., 坐着、看着、拿着.
Result/catching: zháo (2nd tone), e.g., 睡着(zháo) “fall asleep”, 着火(zháo) “catch fire”, 着急(zháo).
Lexical/verb-ish: zhuó (2nd tone), e.g., 着重(zhuó) “emphasize”, 着手(zhuó) “set about”, and nouny 穿着(chuānzhuó) “attire” vs. 穿着(chuānzhe) “wearing (now).”

Can I use other posture/state verbs with 着?

Yes. Common ones:

站着 (standing): 我站着等她。
躺着 (lying): 他躺着看书。
挂着/放着/开着/关着 to describe states: 墙上挂着一幅画。/ 门开着。

What if I want a sequence: “sit down and then wait”?

Use the resultative 坐下:

我坐下等她。 (I sat down and then waited for her.) This is sequential. 坐着等她 is simultaneous (wait while sitting).

Do I need to mark tense? Is this present or past?

Chinese doesn’t mark tense morphologically. 我坐着等她 is tenseless; context or time words decide:

Present/ongoing: add 现在/呢 → 我现在坐着等她呢。
Past: add a time word or 了 → 刚才我坐着等她。/ 我坐着等了她一个小时。

Is 她 only feminine? What about pronunciation?

她 is the written female “she/her.” The male “he/him” is 他. In speech both are pronounced tā; context clarifies gender.

Can I add sentence-final particles like 呢 or 的?

我坐着等她呢。 highlights that the action is ongoing right now.
我是坐着等她的。 (with 是…的) emphasizes the manner in which the waiting happened (typically referring to a specific past event).
A bare 我坐着等她的 is possible for correction/emphasis, but the 是…的 frame is clearer.

What’s a good word-order template with time/place?

Subject + [Time] + [Place] + [Manner (V1着)] + Main verb + Object.

Example: 我今天在门口坐着等她。

Why isn’t there 的 between 坐着 and 等她?

Because V1 + 着 + V2 is a fixed adverbial-like verb chain. 着 by itself links the background state to the main action; you don’t insert 的 there.

Can “坐着” stand alone?

Yes: 我坐着。 = “I’m sitting.” Adding 等她 specifies what you’re doing while in that state.