I feel like professional teachers are usually more reliable. They always (in my experience) give you some material to study, have videos for you to watch, give you some homework... They seem to be more ready to teach as well as more organized and seem to have greater experience with students.

Tutors are MUCH cheaper and dedicated (just browse the website for some time and you'll see some tutors everywhere correcting notebook entries for free to promote their work, even though teachers sometimes do that too), they also seem to be frendlier.

I have to say that I often see tutors with many many students (who are supposed to teach them english) making some terrible english mistakes in their descriptions as well in their students' feedback area.

I also have seen tutors making wonderful things for their students such as teaching them for 2 hours instead of 1, becoming their personal friends, dedicating their free time to correct their students' mistakes, making some wonderful articles for the community, etc.

In a nutshell, it is exactly what you would expect it to be. There are exceptions but professional teachers are more prepared and expensive and tutors are less prepared and cheaper.

If you want to make difficult grammar-related questions and learn new concepts, get a professional teacher.

If you want your teacher to correct your mistakes while you talk to him/her or you want him/her to correct your texts, get the cheapest tutor.

If you want something in between, get a cheap teacher or an expensive tutor.

It depends on what you are looking for.

Professional tutors have more training, in my case it was more than a TEFL certificate. I have been teaching for 7 years. I have seen some good community tutors and you can see that they can even be better than some professional teachers.

You have to check their profile quite well.

I have seen overpriced professional teachers here. I mean if you want to improve just on conversation, getting a community tutor is a cheaper option.

I would agree with @Davi Sales in terms of reliability of Professional teachers. This is our job. We do this for a living so we treat every class like a business appointment. Like for me, even if there is a blackout in my city or no Internet, I have prepared the laptop powerbank and Internet backups because this is a job for me and students rarely have the time to reschedule. Being in this business for 7 years, I know the ins and outs of this business. Professional teachers have a lesson plan at least and it is customized. Every class, I have a pdf file sent to my students, it includes grammar corrections, paraphrasing, YouTube video recommendations additional materials that is why students comeback. I agree with @Phil that there are great community tutors but it also depends on your experience.

I had an Italian student who took classes from community tutors who are still studying in the university or just backpacking. The quality of class is not that good because it is not a job for them. It is just a hobby like what @Phil said. A person who treats a class as a job and a hobby has a different approach.

It's just a temporary means of earning extra income. As a result, the class quality is substandard which should not be.

The experience is different for each person of course.

There are pros and cons. You have to take into consideration your budget, your goals and what you really want.

You have to try in order to know. There are professional teachers with reasonable prices. There are community teachers who can even be better than the professional one's.

For exam preparation though, I suggest getting professional teachers.

Even though I’m a professional teacher, it seems to me that for the most part, there’s very little difference. Community tutors who have done a few hundred lessons and have a high number of lessons per student are certainly providing value. Some community tutors are actually language nerds who love teaching as a hobby, and are quite good at it. Some “professional teachers,” on the other hand, are little more than marketing professionals who jumped through the right hoops (taking some sort of online 120 hour certification course and getting good at Youtube videos for example). In the real world, not every professional (in any field) is truly interested enough in their profession to do what it takes to continuously improve their performance. Sadly, many think that once they have the credentials they know everything. That being said, some relatively high-priced professional teachers are indeed worth every every dollar you pay — I always look at the number of lesson per student (higher is better). Students will say anything, but they’ll continue investing time and money only if the teacher is highly effective. Also, just as a good "informal tutor" will be able to teach, a good professional teacher will be able to provide high quality "informal tutoring". Myself, I’ve had great luck with inexpensive community tutors. Of course, as a teacher, I just need them for practice, and it’s easier to “get lucky” if you’re good at reading between the lines on italki profiles. Good luck in your language learning! (I see we’re both learning Cantonese — if you’d like to PM me, I’ll tell you about my tutors.)

Chun do you mean community tutors vs professional teachers? I've not heard of 'professional tutors' on Italki.

Honestly, the main differences would be how the lesson is approached, the prices, and what you learn in the lesson. Tutors are far more cheaper and useful in learning a language. Professional teachers will often overprice their lessons where it could be $25 to $35 an hour or even more just because they have a certificate or two. No one hour lesson is worth that much money. Also, I often find lessons with professional teachers are a lot more scripted and boring compared to tutors. Tutors go more with the flow and are overall a better quality and cheaper option in my opinion.