If you need to take this class, taking it with Hayes is a great choice. He is an expert in his area. Just google him and you'll find him excellent. If you take it as an easy GE, this may not be a good choice. If you take it due to major requisite, the workload is not that heavy. This course is much more organized and detailed than LING 1, so it is indeed a good intro to linguistics.
The textbook is free and written by Professor Hayes. It's useful to review class materials. Midterm and final is not easy, but they are both open book and the professor gave us about two days to do it. Hayes explained things clearly and gently. He encouraged us to communicate with him in OH.
My TA Matthew is GOAT. He knows Mandarin very well and makes the discussion engaging. I don't know other TAs and professors of this class, but take it with Hayes and Matthew is definitely great.

I would say that this class is a great class for laying a foundation for your future linguistics learning. I admit that Hayes' class is extremely demanding, and sometimes it does take a lot of time to finish the homework and stuff, but I think he is really good at lecturing. I seriously don't understand why people would say that his class is not organized, I strongly argue that it is not true. It is hard, yes, but if you do the reading and do the exercises in the reading, the lecture really is easy peasy(btw I love the textbook he wrote).
The lectures are really great, but I would say that Hayes is not really helpful if you ask him questions in person. I feel like sometimes he doesn't really understand what the students want to ask. I asked him if he could talk about the homework a little bit in class because it was extremely hard, but he somehow thought that I wanted him to postpone the deadline and he told me to just read the textbook. He did acknowledge that he misunderstood me later, but still, it was kind of hurtful. Nevertheless, I would still recommend his class because you can really learn a lot from his lectures.

I am not a Linguistics person (south campus) and found that this class was a genuine challenge at times. It was challenging in a cool way though and I felt like I learned a lot of new things. One thing you should realize about this class is that the professors and TA's are very genuine and willing to work with you IF you communicate with them. Even the concepts that felt like went completely over my head at times, I eventually understood because of TA office hours or an email to the professor. Don't expect to float through this class as an easy GE, I really think it's deeper than that. The discussion section did require attendance but I definitely felt like it was necessary not only to understand concepts but to build relationships with classmates and TA's. By the way the professor wrote the book, and gives it to the class for free use!

I came into Ling 20 thinking it would be easy because I'd heard a lot of people say Ling 20 was "an easy GE," but this class w/ Hayes is NOT an easy class, especially if this is your intro to linguistics (I would stick with Ling 1). Thankfully I already had prior knowledge from taking Ling 1, and that helped a bit, but if this is your first introduction to linguistics, I would say this class is pretty difficult and you kind of get thrown headfirst into linguistics concepts. The homework is pretty extensive and open-ended, and you cover a lot more in-depth content a lot faster compared to Ling 1. The exams are also pretty tough and require you to create new things from what you've learned instead of just regurgitating or memorizing facts. The lectures are very lengthy and quite hard to stay focused in as well, and I stopped going to them. However, Hayes' textbook is really helpful and usually has examples of things you'd see in the homework. Also, Hayes is an incredibly kind and knowledgeable professor, and my TA was also very understanding and lenient.

I changed my major because of this class and this professor. The material of this course are naturally difficult to learn. However, professor Hayes never introduced us to the subject of linguistics even though this is an introductory course, so we basically went straight into the course material not really knowing what we were doing. Not to mention, he began teaching the course with the toughest material: syntax. His homework assignments are very tough. They mainly consist of data sets of words and/or sentences in various foreign languages and fake, made-up languages and asks you to apply course concepts to analyze them. The two exams are basically the homework assignments but 50 times harder.
Lack of organization: This professor along with his TA’s were SO disorganized. They lost my friend’s MIDTERM and a homework assignment of mine. Homework is a large part of your grade in this course, so my overall grade tanked. He gave me the option of redoing and resubmitting that homework assignment for credit, BUT LOST THAT ONE TOO and never responded to my emails, even when I tried to be flexible and send him a follow-up email in case he just missed the previously sent one. I went into this class so enthusiastic and hopeful because of the previously posted reviews on here, but was unfortunately very disappointed.
Take this class with Schutze if you can. He’s a least a little better. Also, try to avoid taking this class if it is offered as an 8am. You must be awake and ready to learn during lectures. He also gives a 1 point quiz at the beginning of every lecture for participation.
Good luck taking this class. I hope you love the subject. I wasn’t obsessed with it and this professor and his class made me not like it very much.

I would not recommend taking this class unless you are absolutely required to. It is very demanding in terms of content and workload, especially for a lower division class. Homework can be difficult at times and requires much time/effort to understand and complete. I suggest going to office hours every week or joining a weekly study group to get through it. The midterm and final were very long and students should have been given more time to take the exams considering the type of questions he was asking. There were several questions on the midterm and final that covered things we had not learned in class. 9% of the class grade comes from daily quizzes given at the beginning of class, if you take it you get credit regardless of your answer. If you miss class you can make up the quiz in office hours. There is also a term paper worth 5% of the grade in which you must interview someone who speaks another language and analyze that language for a certain grammar phenomenon. Hint: avoid Mandarin and Japanese for this assignment. He offers 1% extra credit for participating in an experiment through the psych department. The end of the quarter felt very rushed, which was unfortunate because a good portion of the final had to do with the content that he taught at the end. Hayes wrote the textbook himself and provide a PDF to the class free of charge. One frustrating thing about this class is that the examples he used in class were almost always the same ones from the assigned reading, but he usually is more thorough in class so it is still worth attending. Overall if you go to class, take very, very detailed notes, and study for the midterm and final you should be able to pass comfortably. This is coming from someone who had no prior linguistics exposure.

I took LING20 with Prof. Ozkan (She's usually a TA for this class, but in Summer she teaches it). Attendance mandatory due to daily 10 min quizes. Homeword was tudious, and every time I had to do the self-study since not everything was covered in the class. She gives 3% extra credit for SONA participation. Grading was hard, if even a small mistake is made in a large exercise - you get half credit. Also, it was almost impossible to argue with her about the grades, since she would never accept her own fault. Also, if you took a Ling 1 before, you can easily skip 1/2 of the course material.

Professor Hayes is engaging, funny, kind, and overall a great! Staying on top of your work and asking for help immediately if you're stuck is key because you need to have mastered for the exams. If your goal is to take an easy GE, this is not the class for you (quizzes every lecture, homework every weekend, and not doing your lecture readings will leave you confused in class.) However, if you want a taste of linguistics from a cute and excited phonologist, it's the perfect place to be:)

I truly do not understand why students praise this class. It was by no means easy, it was incredibly intense and the TA (mine in particular) was patronizing and gave me SO MUCH attitude if a concept confused me. There are better professors to take Ling 20 with but if you want to needlessly spend hours studying the material only to be blindsided by how difficult the homework and midterms are, then have at it. I was truly interested in linguistics but this class completely wiped out any interest. Hayes, I'm sure is great, but avoid this class at all costs. It's not worth the stress. This class left me feeling 'stupid' and will only worsen your imposter syndrome. Not worth it. No student should be left feeling stupified because of one class.

Bruce is hands down one of the best professors I've had at UCLA. Anyone who is interested in pursuing linguistics should be excited to know that if you're taking a class with any of the senior faculty of our department you are being taught by world-class linguists. Bruce is an amazing phonologist and is why I ended up pursuing phonological research with such interest.

I implore all linguistics majors to, if they can, take LING 20 with Bruce. He's incredible. His lectures are engaging, thought-provoking, and actually interesting. He's as great a teacher as he is researcher, and makes sure that he presents information in a way that is accessible to everyone. If you're having trouble understanding something he'd be happy to explain, and if you're ever pining for a more in-depth discussion on course content/linguistics Bruce is happy to engage. He also has a great sense of humor, which is something I look back fondly on!

The class itself isn't easy, though -- but there are no surprises. It is the filter class for the Linguistics majors, so you need to get a B+ or above. It is a lot of work. However, if you're truly passionate about the subject and put in the time, you will get a lot out of this class as it is excellent preparation for the upper division courses of the major.