“Ever since I knew how to read, I had always been longing to put down in paper my mother's grieving and turbulent life. That I have never had a chance to do so until I realize that many details are slipping away with the fleeing time and the fear that my inquiry may have my mother relive her sad past, have resulted in this
sketch on what I still remember.”
1. tense; I have always been longing...since I knew how to write.
==> If this is your preference, that is fine. It doesn’t change the tone or the structure of the story.
2. there should be no comma before "have resulted"
==> I don’t know where you learned your English grammar, “should be” this or that. I give you one sentence with a similar structure from The Mayor of Casterbridge, which I am currently reading. Please pay attention to that little comma before “was the perfect…”
"What was really peculiar, however, in this couple’s progress, and would have attracted the attention of any casual observer otherwise disposed to overlook them, was the perfect silence they preserved. " ( from Chapter 1 The Mayor of Casterbridge by Thomas Hardy )
3. the 2nd sentence is too long.
==> How long is too long?
“It seemed that my mother’s fate was predetermined even before she was born – tribulation, gnawing sorrow, and a teary face. ”
1. tense, it seems...
==> This time, your tense preference is not fine. It would be a tense inconsistency error.
2. "a teary face" is a poor choice, use "tears"; "predetermine" is the wrong word, should be "destine", "my mom is destined to ill fate even before..."; for better flow and connection, rewrite the sentence as "...my mother is destined to ill fate--tribulation, gnawing sorrow, and tears--even before she was born. She had never seen her father... "
==> Sportwoman has already discussed about this. I don’t see much change in meaning or translation by replacing “a teary face” with “tears”. Well, I guess the word choice is subjective to personal preference. But “destined to ill fate” is awkward, forgive my bluntness. It doesn’t have that graceful flow and it is so...jarring... it feels like chewing on half-cooked rice that requires double efforts to digest. But people have their own vocabularies and obviously you are quite comfortable using words that way. Fine with me.
