Have noticed that English speakers omit "I" when they are emailing or chatting:
How are you doing?
Am fine.
Also, this occurs often in daily/weekly reports. Have seen quite a few of them, written by nationals of all English-speaking countries:
Was re-installing a workstation in a conference room;
Discussed a quarterly report with X;
Am on an expo in Chicago;
In many languages it is fine, if the subject is obvious or it's a self-reference.
Would like to know, is it grammatically correct in English? If so, where is the borderline?
There's a relevant topic at ELU, "Is it poor form to start too many sentences with I?", but it (1) discusses the opposite side of the question; (2) Suggests to write according to an intended audience or my own taste. This answer seems to be very good, but, being an ELL, am unable to re-write every sentence with a high style like "This opportunity is a good fit for…"
Since in a spoken language the syllable may be very short (which is yet another problem for an ELL), let me focus on a written language only.
Best Answer
There are two phenomena in play in your examples. They are sometimes indistinguishable from each other:
The first phenomenon is that of very informal speak, omitting the word subject I (and sometimes even the verb, as in my last two examples):
Etc.
The other is the use of passive voice. This may be used in formal writing, or when describing something in general, without a specific subject in mind. The implied subject can be "we", "they," "I", "the boss," "the team," or anything else that fits the context. These sorts of things might be seen on an itinerary (in present or future tense), the minutes of a meeting or an executive summary (in past tense):