The modal particle le 了 can be used in the narration of a past situation to mark the end of a series of actions before going on to a new one. In order to maintain the continuity of the narration, it is used at the end of each series of actions, not after each action within the series. The following example shows how the modal particle le 了 marks the end of each series of actions within the bigger picture of what happened after the woman made the phone call.

1. 
   Tā dǎwán diànhuà, liúxià qián, náqǐ shūbāo, jiù chūqu le. Zǒudào xuéxiào dàménkǒur, tā pèngjiàn Zhāng Měiyīng le. Gēn Xiǎo Zhāng shuō-le yìhuǐr huà, tā jiù qù gōnggòngqìchē-zhàn le. Zǒudào chēzhàn, chē hái méi yǒu lái, tā jiù dào pángbiānr de xiǎo shūdiàn qù mǎi bào. Mǎi-le bào, chē yě lái le, tā jiù shàng chē huí jiā le.
   
   她打完电话，留下钱，拿起书包，就出去了。走到学校大门口儿，她碰见张美英了。跟小张说了一会儿话，她就去公共汽车站了。走到车站，车还没有来，她就到旁边儿的小书店去买报。买了报，车也来了，她就上车回家了。
   
   When she finished the phone call, she left the money, picked up her bag and left. When she got to the school gate, she ran into Meiying Zhang. After taking with her for a little while, she went to the bus stop. When she got to the bus stop, the bus had not arrived, so she went to the little bookstore nearby to buy a newspaper. After she got the paper, the bus came. She got on the bus and went home.
   
   
   Note that the first modal particle le 了 marks the end of a series of actions before the woman went out. This series of actions presents a picture of what she did after making the phone call and before she went out. le 了 may not be used after each action is completed, or it would break the continuity of the narration. The next series of two phrases presents the picture of her going toward the school gate, where the action was stopped by an accidental meeting with a friend. Therefore, the second modal particle is used there to mark the end of that sequence. The third series of actions presents the picture of what happened after she ran into her friend. This series was concluded by her leaving to head for the bus stop. Therefore the third modal particle le 了 is used. The next series of actions presents the picture of what she did while waiting for the bus. This sequence is concluded with the coming of the bus and was therefore marked by the fourth modal particle le 了 at the end of lái 来. The whole narrative was concluded by her getting on the bus and finally heading home, which was marked by the last modal particle le 了.



2. 
   Tā dǎwán diànhuà le, liúxià qián le, náqǐ shūbāo le, jiù chūqu le. Zǒudào xuéxiào dàménkǒur le, tā pèngjiàn Zhāng Měiyīng le. Gēn Xiǎo Zhāng shuō-le yìhuǐr huà, tā jiù qù gōnggòngqìchē-zhàn le  Zǒudào chēzhàn le, chē hái méi yǒu lái, tā jiù dào pángbiānr de xiǎo shūdiàn qù mǎi bào le. Mǎi-le bào, chē yě lái le  tā jiù shàng chē huí jiā le 
   
   她打完电话了，留下钱了，拿起书包了，就出去了。走到学校大门口儿了，她碰见张美英了。跟小张说了一会儿话，她就去公共汽车站了。走到车站了，车还没有来，她就到旁边儿的小书店去买报了。买了报，车也来了，她就上车回家了。
   
   
   The example above shows how the continuity would be broken by using the modal particle le 了at the end of each action. Consequently, such narration is unacceptable.

   Different languages have their own ways to deal with this problem. The following example shows one of the ways English maintains the continuity of a narrative. Note that in 3 the subject 'she' is not repeated as it is in 4. It shows how one sentence alone is used to present a series of actions, which maintains the flow of ideas. 4, however, repeatedly uses the subject, 'she'. As a result, 4 is broken into many sentences and becomes a poor and unacceptable narrative.



3. When she finished the phone call, she left the money, picked up her bag and left.


4. She finished the phone call. She left the money. She picked up her bag. She left.
   
   
   “This sense of summing up a situation or bringing a particular topic to a close before going on to a new one by the use of end-of-sentence/clause le 了 may also be found with nominal comments. Compare the following pairs of sentences:
   
   
   孩子今年五岁。
   Háizi jīnnián wǔ suì.
   The child is 5 years old.
   
   孩子今年五岁了。
   Háizi jīnnián wǔ suì le. 
   The child is (now) 5 years old.
   
   
   今天星期六。
   Jīntiān xīngqī-liù. 
   It's Saturday today.
   
   今天星期六了。
   Jīntiān xīngqī-liù le. 
   It's (finally) Saturday today.
   
   
   The first example of each pair only expresses a fact: 'the child is 5 years old' or 'today is Saturday '. The addition of end-of-sentence le 了 conveys the sense of eventually reaching the present situation or position: the child is (now) 5, and today is (finally) Saturday.” (Yip Po-Ching and Don Rimmington: 2004, p. 321)