Arabic seems like an impossible language to learn for most English speakers, but this is due mostly to how strange it sounds. Once you get past the sounds that we don't have in English the language is rather logical and the words are easy to remember. The vast majority of the words in Arabic come from a 3 letter root. You'll have a 3 letter root and variations of that root make different words that are all similarly related. For example, كتب (pronounced kataba) means "he wrote". مكتب (maktab) is a desk. مكتبة (maktaba) is a library. كتاب (kitaab) is a book. There are a lot more words that come from the root kataba, but you get the idea. Sometimes you'll have two words that aren't related at all but which have the same root which can be a little annoying, but most of the time there is some logic involved which really helps in memorizing words. In this respect Arabic is more logical than English. A foreigner learning English has to learn 4 totally different sounding, unrelated words; "he wrote", "desk", "library", and "book", while the Arabic words for these things are all related.
The grammar of Arabic isn't hard to grasp either. The most common way to structure an Arabic sentence is VSO (English is SVO). In Arabic you'd say, "Threw the boy the ball" if you wanted to say the English, "The boy threw the ball." You don't have to say it this way though. You can structure the sentence just like you would in English and they will still understand you. It's just more common to put the sentence in VSO form.
Verb tenses are also much easier in Arabic than they are in English. Easier than Spanish also. I remember trying to learn the Spanish verb tenses in high school and I never knew when to use one past tense or the other past tense. In Arabic there's no worrying about that because it only has 3 tenses (4 if you count the imperative). They are simply past, present, and future. There's no past-subjunctive-progressive whatever. To make a verb future tense all you have to do is put an "s" sound on the front. For past, all of the 3 letter roots are already in the past tense, so you don't have to change them for past tense. For present tense it's a little more complicated, but not much. You put an أ (pronounced "a" as in apple) in front of the root for 1st person present (I write), a ي (pronounced "ya" as in yak) in front for 3rd person masculine (he writes), an a ت (pronounced like "t") in front for both 2nd person and 3rd person feminine (you write and she writes). Those are the basics of the tenses. There is more about the tenses that is slightly more complicated but still really simple compared to other languages.
There are a few sounds in Arabic that English doesn't have, such as the خ which sounds like someone trying to cough up some phlegm and the ق which is like a "k" but is pronounced in the back of the throat. There are also 2 "s" sounds and 2 "d" sounds that are very hard for native English speakers to tell the difference between even with a lot of exposure to the language. Even if you can't tell the difference between some of the sounds you can still know from context what is being said.