How different from Levantine Arabic is Modern Standard Arabic?

Answer 1

The biggest difference is the simplest: that some letters change their sounds, e.g. from /th/ to /t/ or the sounds of the vowels, but in predictable ways. There are also some vocabulary, especially some basic words like "what" and "where" and "not", that are different.

The most important thing, I tell my students, is that most Arabs can understand both to some degree, so when you're starting out, learn to say things one way, and to recognize the other when you hear it. Recent research is showing us that a multi-dialectal approach (learning to recognize new words in several dialects at the same time) allows non-native speakers of Arabic to better attain comfort and confidence in the language.

Answer 2

 no big difference it is only with some words that has been using in the past but now it's not using a lot and some expressions too but it is the same, coz we are getting our grammars from the Levantine Arabic such as poetry and the Holy Quran I mean the old texts.