Past perfect with until

I would argue for a hybrid: “She didn’t realize … until she smoked 10 cigarettes a day.” The smoking of 10 cigarettes a day is a milestone or a marker in this smoker’s process/evolution. The realization happens suddenly. Once the smoker hit this milestone/marker of smoking 10 cigarettes a day, the realization hit her. The word “until” already signals the sequence of the events, and therefore, it is not necessary to use “had”.

In addition, to me "had" serves two functions: 1. as the past perfect, and/or 2. implying the act (verb) is a lengthy(ier) process.

helo

I don't think either versuion conveys the meaning well. I would argue for "until she was smoking..."

The correct sentence is: "She didn’t realize that she was addicted to nicotine until she had smoked ten cigarettes a day."

This is because the past perfect tense ("had smoked") is used to indicate an action that occurred before another past action or point in time ("realized"). In this case, smoking ten cigarettes a day happened before she realized she was addicted to nicotine. For more info read comments on https://kingessays.com/. Academic institutions promote research and scholarly inquiry across various fields, encouraging faculty and students to contribute to the advancement of knowledge through original research, publications, and creative works.

Both sentences are grammatically correct, but they convey slightly different meanings due to the use of different tenses.

1. "She hadn’t realized that she was addicted to nicotine until she smoked ten cigarettes a day."
This sentence says she didn't know she was addicted until after she smoked ten cigarettes. The not knowing happened first.

2. "She didn’t realize that she was addicted to nicotine until she had smoked ten cigarettes a day."
This sentence says she didn't know she was addicted until after she had already smoked ten cigarettes. The smoking happened first.

She didn’t realize that she was addicted to nicotine until she had smoked ten cigarettes a day.

This is because the past perfect tense "had smoked" is used to show that the smoking occurred before the realization. So, her smoking ten cigarettes a day happened first, and her realization of being addicted happened later.

Both sentences are grammatically correct, but they emphasize different sequences:

"She hadn’t realized that she was addicted to nicotine until she smoked ten cigarettes a day."

This suggests that the lack of realization (not knowing she was addicted) continued until she reached the point of smoking ten cigarettes. The not-knowing came first.
"She didn’t realize that she was addicted to nicotine until she had smoked ten cigarettes a day."

Here, the past perfect "had smoked" clarifies that she smoked the cigarettes before her realization.

Would removing the negation help with clarity? As in:

"She (only) realized she was addicted to nicotine after/when she started smoking 10 cigarettes a day."

One could add 'only' to emphasize the sequence of events.