Do native Japanese speakers always omit い after て in present continuous tense across all conjugations in informal language?


  * 言っている > 言ってる
  * 欲しがっています > 欲しがってます
  * 見ていた > 見てた
  * 行っていました > 行ってました

I'm trying to sound as native as possible, so I would like to know which the
more common way is of speaking in the present continuous tense (while knowing
that the grammatically correct way would be to include い after て).




That happens very often, but it would be overgeneralizing to say that it
**_always_** happens.

There are multiple levels of "informal speech" and it would be safe to say
that the more informal the situation/conversation becomes, the more often the
phenomenon in question occurs.

(It is not too informal to end sentences with 「ます」 or 「ました」 as in a couple of
your example sentences, either. Sorry, but as a native speaker, I can't help
noticing these little things here.)

