Since Mandarin Chinese is taught more and more in schools, I've noticed there are many more resources to learn Mandarin Chinese as opposed to Cantonese Chinese.

For Mandarin Chinese speakers, was it difficult for you to learn Cantonese? And Cantonese speakers, was it difficult to learn Mandarin? I understand that the dialects pretty much share the same written system for the most part, but I was wondering if one dialect is easier to learn than the other.

You can learn either one. I would probably chose Mandarin first when you plan to use it in China. But outside China Cantonese is the number 1 Chinese language.

A few wrongs posted before:

Not everybody in China know Mandarin, about 60% know it.

Most people in Hong Kong do not know Mandarin.

The writing system is the same (ok, China uses simplified, Hong Kong traditional characters), however, the written language does not match Cantonese that well since structures are often different. To give one example, in Hong Kong people don't say ???

Cantonese has 6 tones. Mandarin 4. But you don't have to learn tones. Just learn how to copy and forget the tones.

Important aspects for learners: Mandarin has much more learning resources.

Specially if you want to learn the written language Mandarin will be easier.

In principle, they are equally easy to learn. As an adult 2nd language learner, there are way more resources for learning Mandarin. Also, people have been teaching Mandarin for a long time, so teacher know the typical pitfalls. This is not the case for Cantonese. Finally, as a literary language, Mandarin has a fairly well understood grammar, while there are relatively more aspects to Cantonese grammar that we still do not understand. (Although there is an increasing written culture for Cantonese in Hong Kong.)

Not to mention that you will be met with less resistance if you try to learn Mandarin. People still ask me, "Why would you bother learning Cantonese? That's not the official language of China?" We all have our own reasons for learning the languages we want to.

The tonal system of Cantonese is slightly more complicated, but Mandarin has consonants that are more difficult for English speakers to grasp. All in all, there are some aspects of Cantonese grammar that are more difficult than Mandarin, and some aspects of Mandarin grammar that are more difficult than Cantonese; however, you will have a larger support basis for Mandarin.

As a final note, if you have a close friend who speaks one of the two that you can practice with, then I would vote for learning that one. Having a speaker to practice with is the best way to learn.

As a Chinese native speaker, I believe Mandarin is more important than Cantonese, because even in Hong Kong, most people are also able to understand Mandarin. The major difference is just in oral language between Mandarin and Cantonese.

I prefer to learn Mandarin first. Because it is more important to learn Mandarin than other dialect when you learn Chinese. Every one around China can understand Mandarin, but only a small part of population can understand Cantonese. Check this site http://www.hellomandarin.com/, and it tell you more about Mandarin.

depends on your intentions. Both dialects are unintelligible to each other. Someone speaking Mandarin can only understand Cantonese if they took time to learn it in an environment where Cantonese spoken most, but beware, the person's own dialect might be lost if they speak the other one too much. The opposite is also true. Someone who speaks Cantonese might not be able to quickly learn Mandarin due to Mandarin's number of tones at 4, which is way less than Cantonese at 9.

Mandarin and Yue (Cantonese) are different, although closely related, languages, so learning one and then the other is like learning French and then Spanish. The difference is that Mandarin and Yue share a writing system. Mandarin is probably easier since it has only four tones. Yue has eight tones (with some dialects having as many as ten). Yue has also preserved more of the Middle Chinese sound system (including about a dozen more syllable-final consonants). I can't speak for the grammar, but the sound system of Yue is more difficult for an English speaker to learn than the sound system of Mandarin.