May I list Three of mine, all in the field of general grammar?
1) Correct use of Possessive Pronouns, especially "its" (N.B., no apostrophe [hint!] for missing letter(s)`)
2) "Inclusive" language questions I have
3) Split Infinitives
1) First Objection: Do not use "it's" exclusively. Always Correct your "chellspecker." Remember, IT'S is a contraction either of "It Is" or of "It Has." It's clear to me that its use is not clear to lots of people. Other Possessive pronouns are My, Our, Yours, Your, His, Hers, Their(s) and ones —or maybe one's, cannot figure that one out exactly.
I wish people would show off their mastery of this rather simple grammatical parsing more often:
It's a long time since that subject raised its ugly head.
It's been more than a year since my car's had its tires rotated.
It Has been more than a year since my car Has had (His, Her, or Its) tires rotated.
2) I dunno why, but although I do try to use "his or her" most of the time when some sort of scenario is involved, I find it very difficult to stretch quite that far when the subject is some sort of evildoer or culprit. Am I really wrong just to refer to the person as "him?" I try, whenever possible, to avoid the rather clumsy "Her or His" by putting things in the plural, but sometimes that just doesn't work.
3) Frankly, split infinitives don't much bother me (Sometimes there's really no graceful way around them.). However, I plead one blatant Miscreant: Using the word "NOT." That conveys ugliness and severe carelessness to me. I definitely think it breaks the Fourth Precept, in that it makes no attempt at correct speech. "To not care," what sort of ugly knot is that?
However. I do think that language should be tied to the pictorial, to story, as closely as possible in order to keep it real; and that the split infinitive is a rather rude interloper. In other words, some sort of art or skill should be aimed for always. By skill, I mean the sense of keeping the letters distributed so as to relate things as they actually unfold. You get more a sense of this when you read translations of things from languages with pictures as their alphabet, such as from the Chinese. (In Latin, the singular form for the individual characters is in the singular— and the plural form refers to a written correspondence. Now that is interesting to me.)
Now, I submit that there is not a subtle difference between "The rabbit tried to completely hide from the hunter" and "The rabbit tried to hide completely from the hunter." Well, there's nothing subtle in my mind, at least. In the latter I can sense more the sense of ongoing time: the rabbit is already hidden, but it continues to try to hide deeper, more completely. The Main point is the Hiding, not the rushing to complete the Deceit! HA!
https://en.wikipedia.org/wiki/Split_infinitive (See especially the Paragraph with Note 19.)