Neutral:
* Corrector: This is a general term, often used in a formal context.
* Editor: This is used when someone is correcting written speech.
* Grammar Nazi: This is a more informal and sometimes humorous term.
* Language purist: This term implies a strong adherence to grammatical rules.
Negative:
* Pedant: This term implies someone who is overly concerned with details and rules, often to the point of being annoying.
* Nitpicker: Similar to pedant, this term emphasizes the focus on small details.
* Grammar police: This term is often used sarcastically, implying that the person is overly critical of someone's speech.
Positive:
* Mentor: This suggests the person is helping you improve your speech skills.
* Teacher: If the person is providing formal instruction, this term is appropriate.
* Coach: This implies someone who is guiding you towards better communication.
The best term to use depends on the specific situation and your relationship with the person.
Remember, it's always important to be respectful when discussing someone's language choices, even if you disagree with them.