I picked up the habit of skipping "I am", as in "Looking forward to it" instead of "I'm looking forward to it" — is this incorrect? [duplicate]

I picked up this habit from a friend, who skips "I am"/"I'm" most of the time:

• "[I'm] going to work on that."
• "[I'll] keep you posted."
• "[I'm] not sure about that."

Is this completely incorrect, or accepted casual language?

Solution 1:

Pro-drop language

English is not a pro-drop language. Nonetheless, subject pronouns are almost always dropped in imperative sentences (e.g., Come here), with the subject "you" understood or communicated non-verbally.

In informal speech, the pronominal subject is sometimes dropped. This ellipsis has been called "conversational deletion" and "left-edge deletion", and is common in informal spoken English as well as certain registers of written English, notably diaries. Most commonly, it is the first person singular subject which is dropped.

Some other words, especially copulas and auxiliaries, can also be dropped.

• [Have you] ever been there?
  [I'm] going to the shops. [Do you] want to come?
  [I] haven't been there yet. [I'm] going later.
  Seen on signs: [I am/We are] out to lunch; [I/we will be] back at 1:00 [P.M].
  What do you think [of it]? – I like [it]! (the latter only in some dialects and registers)
  [Do you] want a piece of cake?

Source: Wikipedia

As mentioned earlier in the comments, omitting the subject pronoun with the copular verb (be) is commonly used in conversational English when it is clear who the speaker is referring to, either themself or a third party.

• Been to the shops yet? (Have you been to the shops yet?)
• Had a great time last night. (I/we had a great time last night.)
• See you soon (I'll see you soon.)
• Look forward to it (I'm looking forward to it.)