Has imported words from the surrounding languages (Persian, Hebrew, Aramaic, Turkish, and so on) and has certain meanings or spellings changed over time? Are there specific phases of Arabic linguistic history such as Old English, Middle English, and Modern English?
I'd suggest asking over at /r/linguistics. Not that you won't get an answer here, but they specialize on this and stuff
To clarify for others what you mean by English changing, English went through a radical change as a result of the Norman conquest in 1066. Old English is unintelligible to modern speakers. Slowly, over the course of 250 years, Norman French and Old English merged into one language. The merge was not 50/50, and modern English still has much more in common with Old English than with Norman French. But a lot of vocabulary changed, and English largely lost its conjugation according to subject. "To be" and the third person singular "s" are two examples of where modern English still retains conjugation according to subject. Since 1300, English has gone through some other changes, most notably the great vowel shift, which occurred around the time of Chaucer. Not too long after Chaucer, the "e" at the end of many words (e.g., "come") went silent. As English was standardized in the 1500s and due to the writings of those such as Shakespeare became popular, English has evolved much more slowly.
That being said, I can't compare the evolution of English to other languages since I'm not nearly as familiar with how they evolved.
I am no expert but I am an Arabic student and can give a really base answer.
Arabic does have loan words, and incorporates them very happily in with the language. The word for computer is Kombuter, cell phone mobayl, etc. It has somewhat of a phase, except that the first phase is unique in that it is still widely in use. Quranic, or Classical Arabic, constitutes the earlier recordings of the Arabic language we have, and eventually gave rise to Modern Standard Arabic, the uniform 'scholarly' form of Arabic spoken across the Arab world. At the same time, many tribal tongues began, as they were being written down, to incorporate the perso-Arabic alphabet, giving rise to the dialectal cluster fuck that is colloquial Arabic. I have no doubt that there was an early Arabic form, but whether or not we have it recorded anywhere or not remains to be seen. It is worth noting that Arabic is heavily related to Aramaic and Hebrew, and the actual writing system itself evolved from Aramaic.
Beyond that, I don't know.