How to properly use verb stem instead of the te form?


I'm writing an essay for school and to keep the word count down I've been
using the verb masu form's stem instead of the te form.

However, I'm slightly confused by how consistent it needs to be. Does it only
need to be used when you're linking two clauses or in every situation with the
te form.

For example:

> 今、電車を乗ってい、音楽を聴く。

or would it be

> 今、電車を乗りい、音楽を聴く。

Another example:

> このケーキは美味しくて甘く、この紅茶は苦い。

or would it be:

> このケーキは美味しく甘く、この紅茶は苦い。

Similarly how would this construction work with grammatical constructions that
require the te form such as てから or てくれる, etc.

Apologies for the poor examples, I'm not able to use my real essay examples
because of plagiarism.




As a starter, please keep in mind that the masu-stem (aka 連用形) and the te-form
are **different concepts**. They work somewhat interchangeably [when the stem
is used in a situation called
中止法](https://japanese.stackexchange.com/q/9771/5010), but in most other cases,
they are two different concepts, each with many unique usages.

  * [Do I have a good grasp on the basics of what the continuative form is?](https://japanese.stackexchange.com/q/65936/5010)

In particular, subsidiary verbs ONLY take the te-form of a verb. 乗っている is fine
but 乗りいる is wrong. 食べてみる is fine but 食べ見る is wrong.

  * [What is a subsidiary verb?](https://japanese.stackexchange.com/q/18952/5010)

い doesn't work as 中止法 although い is the masu-stem of いる. You have to use おり
instead. This is an important exception you have to remember.

  * [Does anyone know which おり this is?](https://japanese.stackexchange.com/q/3334/5010)
  * [meaning of "~しており、...."? isn't that 謙譲語{けんじょうご}?](https://japanese.stackexchange.com/q/14698/5010)

If you want to list two progressive actions (e.g., "I am walking and talking")
you have to add ている to the second verb.

In addition, 電車を乗る is wrong. You have to say 電車に乗る.

Thus the following sentence is ungrammatical in three or four ways:

> 今、電車を乗りい、音楽を聴く。

The corrected version is:

> 今、電車に乗って音楽を聴いている。  
>  今、電車に乗り音楽を聴いている。  
>  I'm on the train and am listening to music.

