How hard is Greek to learn?

Your mileage may vary. In any case, we have this thread for online resources http://discourse.textkit.com/t/resources-suggestions/10411/1

That’s an almost impossible question to answer, because it depends (“mileage may vary”). It depends greatly on your previous experience with languages, your level of commitment, whether you are learning on your own or in a classroom environment. In general, speakers whose first language is English will tend to find inflected languages such as Greek and Latin more difficult than learning a language such as Spanish, which is not. Personally I found German more difficult than either Latin or Greek, and Hebrew easier than either.

Dear Adrienne,
Do you mind if I ask you why it matters to you how “hard” it is? Learning any language is hard, isn’t it? The experience for me is enjoyable and gratifying, but it takes a dedicated effort, as I’m sure you know.

Again, if I may ask, what’s your interest (or passion?) in learning Greek?

Harder than Spanish? Probably, assuming you want to learn classical Greek. Even koine Greek would qualify. A few suggestions about online resources. The discussion forums are a mixed bag, you need emotional body armor, like an armadillo, to survive. I dabbled in koine Greek for over a decade prior to joining a discussion forum. I learned a lot from reading the posts then eventually decided to opt out. Then I decided to go underground an post under a pseudonym changing the gender. I also adopted a different persona. That worked fairly well, got more respect as a woman. Got tired of that and came back under my real name. I suggest you tread lightly in the forums until you have perused the archives extensively to get the flavor.

Before you can address the question of whose online resources you want to use you need to decide on what sort of learning methodology suits your purpose. This is currently a highly controversial subject. I wasn’t faced with this decision 30 years ago. My reason for dabbling in Greek was linked to studying generative grammar. I found an author in my own library who was suitable and used his book. By contrast today you’re confronted with a smorgasbord of options. Advocates of second language methodology are very noisy right now, if you can find a community where classical Greek is spoken fluently on the streets then go for it.