Given the Question and Answer pair, detect whether the answer is acceptable or not. Denote acceptable answer as "yes", otherwise denote as "no". An acceptable answer is consistent with the context in question, detailed, long, and uses general knowledge of English. Answers that are not definite and suggest a variety of options are not acceptable answers.

Question: English isn't my mother tongue, and when we recently talked to a native speaker (during some company audit), he pointed out that the plural word "trainings" is actually wrong (he pointed that it is a very common mistake and was almost amused by it). I couldn't understand why and wondered what the correct plural of "training" would be. Online Dictionaries/Thesaurus don't answer it, so it's probably another opinion-based statement. I haven't found a source to back it up, though.
Answer: I agree with Mick that training is an uncountable noun. In the example given by Mr. Fine of a specific training event allowing training to become countable, I disagree. In the case of becoming countable, the portion being counted is the event. Therefor, it would be "there are multiple training events available at the pavilion" (or whatever). I see many cases where much effort is made to "fix" the plural when a simple rewording will eliminate the contentious context and allow an, arguably, better flow by using the standard form.
no

Question: Is penultimate commonly used in English, or are its variations (such as second to last) more common? I need to use it in conjunction with the expressions First Payment Date and Last Payment Date to name variables while programming. In my mother language (Portuguese) Penultimate Payment Date would be fine, but it feels strange in English. (I know feels strange is not very helpful, but I'd like to know how to convey the meaning in the most natural way.)
Answer: Someone I know who is a native speaker of Spanish and a professor at a university in the United States has complained that when he used the word "penultimate" in class, the students don't know what he's talking about. The word is perfectly, unimpeachably, 100% correct. It is a bit of an upscale, literary word though. It certainly is a "term of art" in fields like linguistics, where it is used commonly to refer to syllables. I searched for the word in the Corpus of Contemporary American English, and divided the results by section: spoken, fiction, magazine, newspaper, and academic, and got these results: spoken: 10 fiction: 53 magazine: 55 newspaper: 36 academic: 93 total: 247 So, it is certainly used in all areas of English, with a moderate skew towards higher registers like academic writing. Depending on the intended audience, a writer contemplating using the word "penultimate" should consider that there is a relatively high likelihood that word will not be understood. Instead of "penultimate", the phrasing in common usage is either "next to last" or "second to last". Both of those should be universally understood. Interestingly, Google Ngrams shows that the word "penultimate" rose in usage (in published books) steadily from 1800 to about 1990, and since 1990 it has shown a steep dropoff, taking us back to usage levels from the late 1960s. The better-understood terms "second to last" and "next to last" are less common (again, though, in published booksGoogle Ngrams tells us nothing about spoken usage), with "next to last" having more historical usage but a slow tapering off of usage since 1960 and "second to last" increasing in usage from 1970 on, with both enjoying approximately the same usage today.
yes

Question: Sometimes people are referring to mechanical objects as "she": I love my car. She always gets the best service. Are there any rules when it is appropriate to use "she" instead of it, and is "he" ever used in such context?
Answer: The pronoun "she" is sometimes used to refer to things which can contain people such as countries, ships, or vehicles, or when referring to certain other machines. This, however, is considered a stylistically marked, optional figure of speech. This usage is furthermore in decline and advised against by most journalistic style guides such as the Chicago Manual of Style.[9] If used, the terms she, her, and hers are always used, regardless of the entity's name - for example, "The U.S.S. John F. Kennedy (CVA-67) was laid down October 22, 1964. She was launched on April 1, 1967..." "He" in reference to an inanimate object has not, as far as I'm aware, ever been common usage in English.
yes