Usage of っ inbetween て and た forms?


I have seen quotes in manga and games in which a verb will be presented as (If
I remember correctly) "しまっていった" as opposed to "しまっていた".

Why is this? Is this an anomaly? Is one form intentionally used to convey a
different meaning? If the latter is the case, what are the differences in
meaning?




いた is the past form of いる, and いった is the past form of 行く. They are Japanese
[subsidiary verbs](https://japanese.stackexchange.com/q/18952/5010) with
completely different functions.

  * **(-て)いる** : progressive form ("is V-ing") or continuation of a resultant state ("has V-ed")
  * **(-て)いく** : physically or psychologically going away from the speaker; gradually over time toward the future; do something and leave

When used as a subsidiary verb, (-て)いく and (-て)いった are usually written in
hiragana. See: [Difference between -ていく and
-てくる](https://japanese.stackexchange.com/q/676/5010)

For example:

  * 雪は溶けていた。  
The snow has (already) melted.  
(Someone only found a wet road and puddles.)

  * 雪は溶けていった。  
The snow (gradually) melted away.  
(Someone was observing the melting process.)




いた is the past form of いる, and いった is the past form of 行く. They are Japanese
[subsidiary verbs](https://japanese.stackexchange.com/q/18952/5010) with
completely different functions.

  * **(-て)いる** : progressive form ("is V-ing") or continuation of a resultant state ("has V-ed")
  * **(-て)いく** : physically or psychologically going away from the speaker; gradually over time toward the future; do something and leave

When used as a subsidiary verb, (-て)いく and (-て)いった are usually written in
hiragana. See: [Difference between -ていく and
-てくる](https://japanese.stackexchange.com/q/676/5010)

For example:

  * 雪は溶けていた。  
The snow has (already) melted.  
(Someone only found a wet road and puddles.)

  * 雪は溶けていった。  
The snow (gradually) melted away.  
(Someone was observing the melting process.)

