Arabic has a very powerful root system. Once you learn the grammar, you will be able to guess many vowels. Moreover, you will develop intuition over time. But some ambiguity will persist mainly with regard to words that are not based on any root, and rest assured that even many Arabs pronounce such words differently from what you can find in dictionaries. As far as understanding is concerned, I can warmly recommend the paid Oxford dictionary: https://premium.oxforddictionaries.com/arabic/ https://global.oup.com/academic/online/subscribe/?type=listing&subjectcode1=1803195%7CGEN00010& A detailed description of its features: http://drbulbul.com/2017/06/14/online-arabic-dictionaries/

Simply if you can understand the English words without vowels! i.e. in a simply way Fatha ( َ ) is like short "a" Madd Fath ( ّّ ) is like long "a" Dammah ( ُ ) is like short "o" Madd Damm is like long "o" Kasrah ( ِ ) is like short "e" Sokoon ( ْ ) is like no vowels. and so forth... Therefore, it comes by practice and experience, Arabic is a rich language as it is simple. My recommendation is to practice, practice then practice.

The context might help you understand the meaning of some words.

From the context.

You can understand it by context . Hope you keep improving your Arabic , Good luck :)