Learn Hardcore Chinese: wǒmen xiàbān yǐhòu chángcháng yìqǐ zǒu huí jiā.

Avoid putting 一起 before the time phrase, and avoid splitting 一起 from the verb phrase it modifies. Also, you don’t need 在 before 下班以后 in everyday speech.

Why is there no 了? Shouldn’t past actions take 了?

No, because this sentence describes a habitual action (signaled by 常常). Chinese generally does not use 了 for habits. Use 了 for specific, completed events:

Habit: 我们下班以后常常一起走回家。
One specific past time: 昨天我们下班以后一起走回了家。

What’s the difference between 走, 走路, and 走回家?

走 can mean “to go/leave” or “to walk,” depending on context. Alone in everyday speech, 我走了 often means “I’m leaving.”
走路 specifically means “to walk (on foot).”
走回家 means “to walk back home,” where 走 is the motion, 回 is the direction “back,” and 家 is the goal.

You can also say 走路回家; it’s a bit more explicit about going on foot. Both are natural.

Why do we have both 走 and 回? Isn’t that redundant?

They do different jobs. This is the common Chinese pattern “motion verb + directional complement (+ goal).”

走 = the manner of motion (walk)
回 = the direction (back, return)
家 = the destination

So 走回家 = walk + back + home.

Can I just say 回家 without 走? What changes?

Yes. 回家 simply means “go back home,” without specifying how. If you want to specify on foot, add 走 (or 走路), or a transport verb:

回家 (go back home; method not stated)
走回家 / 走路回家 (walk back home)
坐公交回家 (take the bus home)
骑车回家 (ride a bike home)
开车回家 (drive home)

What’s the difference between 回家, 到家, and 回到家?

回家: head/go back home (orientation). Depending on context, can mean starting to go home or having gone home.
到家: arrive home (result achieved).
回到家: return-and-arrive home; emphasizes both returning and the arrival result.

Example:

On the way out: 我回家了。 can mean “I’m going home now.”
Upon arrival: 我到家了。 = “I’ve arrived.”
Narrative emphasis: 我们走回到家了。 (a bit heavier, stresses both the return and arrival; 走到家了 or 走回家了 are more common.)

Where exactly should 一起 go? Is 在一起 the same?

一起 (together) goes before the verb phrase it modifies: 我们…一起走回家.
在一起 means “to be together (in the same place/relationship)” and is used differently: 我们在一起。 = “We are together.”

So don’t replace 一起 with 在一起 in this sentence.

Can I move 常常 around? How does it compare with 经常 and 常?

常常 and 经常 both mean “often.” 经常 is slightly more common in speech in many regions; 常常 is perfectly fine. 常 is concise and a bit written/formal.
Position: Frequency adverbs usually come before 一起 and the verb: 我们下班以后常常一起走回家。 Other natural positions:
我们常常下班以后一起走回家。
下班以后我们经常一起走回家。

What about 以后 vs 之后 vs 然后?

以后 and 之后 both mean “after,” with 之后 sounding a bit more formal. Here both work: 下班以后/下班之后.
然后 means “then/and then” (a sequence connector), not “after.” You could say: 下班以后，我们常常一起走回家，然后做饭。

Do I need to say 我们, or can I drop the subject?

Chinese often drops the subject if it’s clear from context. If it’s already known you’re talking about “we,” you can say:

下班以后常常一起走回家。 If you need to establish or emphasize the subject, keep 我们.

What exactly does 下班 mean? Is it the same as “finish work”?

Yes. 下班 means “to get off work/finish one’s shift.” Its counterpart is 上班 “to go to work/be on duty.”

下班以后 = after getting off work. You may also hear 下班了以后; the 了 highlights the completion of that event, but for a general habit it’s usually omitted.

How do I say we often go home together by bus/bike/car in the same structure?

Keep the same slots and swap the manner-of-transport:

我们下班以后常常一起坐公交回家。 (by bus)
我们下班以后常常一起骑车回家。 (by bike)
我们下班以后常常一起开车回家。 (drive)

Pattern: Subject + Time + Frequency + 一起 + [transport verb] + Goal.

Why is 一 in 一起 pronounced yì (fourth tone) instead of yī (first)?

Tone sandhi rule for 一:

Before a 4th-tone syllable, 一 becomes 2nd tone.
Before a 1st/2nd/3rd-tone syllable, 一 becomes 4th tone. Since 起 (qǐ) is 3rd tone, 一 changes to 4th tone: yìqǐ.

Should I add 来 or 去 after 回家, like 走回家去?

You can, but it’s often unnecessary when the destination is explicit.

走回家去 emphasizes movement away from the current location toward “there.”
走回家来 would mean “walk back home (to here),” which is rarely needed unless contrasting locations. In most cases, 走回家 is the most natural and concise.