Him/her, her, their... What to choose for referring to somebody whose gender is unknown?

Dears Contrex and Max and Dalehi and Fil
According to what I got from this thread using either "they" or "he" as a neutral pronoun is accepted. Am I right? Please correct me if I am wrong.
What about "she". Could it be used as a neutral pronoun?
Can I have a one final word? e.g. Can I use always "he" as a neutral pronoun?
(please elaborate your answers in case of commonly used English and a formal grammatically correct English like a TOEFL exam)
Thanks in advance.

This article about American English is pretty interesting.

https://en.wikipedia.org/wiki/Singular_they#Trend_to_prescription_of_generic_he_from_19th_century.

Apparently using the singular "they" to be gender neutral has been around since the mid-1800s.

Sorry, I don't know what to tell you for your TOEFL. It depends on the scoring rubrick. Our culture is changing and I could go either way on this. I found one source that suggesting avoiding the use of the singular "they" on the TOEFL and to go with "he or she". I don't know if this constitutes good advice.

I am sorry that isn't a very helpful answer. Is there a style guide used for the TOEFL?

Just now I had some searches about " Thanks in advance" and I saw such a strange comment about it:"If you thank someone in advance for something they have not agreed to do it is considered rude as you are pressuring them unduly to acquiesce or be put in a bad position to refuse you".
I just wanted to tell you all that for me there is no such things and I didn't mean that. Excuse me if it implied that. I won't use it again.

1-Does it mean that in a formal situation like TOEFL exam it is accepted to use "he" in such a case?
2- Also somewhere not quite formal like here in A2K can I say: "Somebody who is chosen for this position must be talented. Also, they must be hardworking."?

I don't take any offense (or feel any pressure) to you saying "Thanks in advance". It is a little formal, but I just take it as saying "I appreciate any effort you make for me".

I am thinking that if I were taking the TOEFL, I would use "he or she" in this case just to be safe.

"Somebody who is chosen for this position must be talented. Also, he or she must be hardworking."

On A2K you shouldn't worry. There are no rules here. Write however you like. As long as we understand what you are saying, you are doing well.

Not just TOEFL Max, I will use "he or she" for it.
But I want to know you, yourself, do you choose "he or she" in a formal speaking for example speaking to somebody whom you are not familiar with?
I've been here in A2K for months and I've seen "he or she" just once in the whole this time, so I can guess that it is not a commonly used term. So what to choose? Can I use "he" without worry?
You know, I am not native, so I cannot avoid awkward phrasing in some cases. I just want to have a guide. I've seen using "she", "he", "they" all of them as neutral pronoun. I want to have a guide what to choose in such cases? (for example speaking to somebody who I don't know well and I want to keep safe but I do not want to use he or she lots of times speaking about somebody whose gender is unkownn. You may admit that it's unusual to be so)
Also thanks for your hint about using its rather than "it's". It was my slip of tongue.

I just responded to another thread here where I used the singular "they" without thinking about it. It made me laugh when I noticed I had used it.

I think I alternate between using "he" as a gender-neutral pronoun, and the singular they. I do this without thinking. I don't think I can tell you the pattern (maybe if I think more about it I can figure it out). I think I sometimes will write "he or she", but this is generally when I am specifically trying to avoid offending someone (i.e. at work).

In truth I don't worry about it or think about it very often.

That's not very helpful advice.

Hopefully you have found Americans to be pretty easy-going and not too uptight about these things. I can't speak for all Americans, but generally I don't make a big deal about slip ups, particularly with people I know are English language learners.

I speak a second language too, so I understand how difficult it is to get the phrasing correct.

In some reference books where unknown genders will be referred to, the authors/editors note that they will alternate he/she by chapter.

He or she isn't a formulation in common use. In most cases, they is preferred.

Thanks mom,
So from what you and dear Max said that he has just used "they" without thinking, I can conclude that "they" should be my first preference (not in case of TOEFL or things like that but rather in not quite formal situations like what I face here in A2K), then the next preference would be"he". Am I right?
Noticing that Max said he alternates between "he" and "they".
As a sample in my last sentence which one will you choose? (supposing that u don't know the gender)
1-Noticing that XYZ said he alternates between "he" and "they".
2-Noticing that XYZ said they alternate between "he" and "they".

Sky no offense but are you sorta kidding those other fellas (and gals)

Really? My apologies
Just for a few laugh when I was kid, I was used to ask anybody who was around me of everything! I do not forget when my family laughed at me when I asked them which one's speed is more? camel or cat?
I think I am over questioning! So excuse me all. I got my answer.

I would not use he as an alternative to he or she.

We don't know Max's gender?

Nah Sky what the hell anyhow

Unnecessary, power pwr to ya

Most remarkable phenom

Again and again, one more time, repeatedly, another instance calling for more profile

At least one of us does. On the internet gender shouldn't matter.

Beth sure it does, along w/ age, nat'l ed., loc, interests, rel, kids, obj's, yield insight for response

Gender fluidity is becoming more visible, if it doubt the acceptable term to refer to trans people is 'they' regardless of whether or not there's one or more people being discussed. That way you won't cause offence.

I guess I understand what you mean by that. It was a good point. Yes, I admit that.

I know. I said "suppose" that we don't know. But in some cases I must acknowledge that it's not clear to understand the gender from just the name. (not in case of dear Max)

Father I try to be conservative in asking questions because in some cases I've bothered my teachers and other colleagues by my over and over questions. I just thought that this time is one of them.Thanks.