Can you list them here so I can use it as a reference later on?

Some common native speaker errors include difficulty with tricky subject-verb agreement, especially with indefinite pronouns and compound subjects using "or." Another common error is creating a "double negative." This could happen with words the writer or speaker may not realize are negative:
*This hardly never happens. (This hardly ever happens.)

Another mistake that native speakers make is that they may not know the past participle of some irregular verbs, so they use the simple past with has, have, or had.

*He had went. That should be He had gone.

Sometimes native speakers choose the wrong word from a pair of words that sound similar or the same to them:

affect, effect hear, here

Thank you for this post. This information is relevant for me too

Students: We have free audio pronunciation exercises.

If you still need information, I can tell you what I have trouble with...

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Who v. Whom

Who should I say is calling?

She is the best person whom I can recommend.

Lie v. Lay

One criterion / two criteria (pl.)

Datum / data (pl.)

Hyphens with compound adjectives (I have to check style guides a lot)

5 years' experience / 5 years of

Remnants of subjunctive - if I were you.

(N.) Americans are losing the ability to tell the difference between simple past and present perfect.

Future will decision on-the -spot vs. Future plans "going to"

- native speakers confuse this. Some ESL teachers recommend not teaching it until students are in more advanced stages.

**Note: Reflexive pronouns are sometimes used to mean "also." It is rare or a dialect. I thought it was a mistake when I heard it. (My mistake!)

"I think so myself."

Dangling/misplaced modifiers in writing, especially at university level.

What are some grammar rules that even ntive speakers have trouble with?

I understand this question, and I support the responses you have received, and I understand why rules are important to you.

But note that the majority of native speakers know very few grammar rules. Many of the learners on this forum know many more grammar rules. However, reasonably well-educated native speakers commoly know a good sentence when they hear it, and can commonly produce good English.

Clive

Teachers: We supply a list of EFL job vacancies

The English language can be hard even for native speakers sometimes. Everyone can make mistakes, no matter how long they've been studying and speaking it. And to be honest, that is normal. When you're making mistakes in speaking, you're one step closer to progress in the language you're learning. Some of the most common mistakes are the following: the wrong usage of "good" and "well", "fewer" and "less", "me" and "I", "every day" and "everyday", "your" and "you're", "that" and "who" and many more.