If you see a Hamza at the end of the word, you have to watch out. In the example of the Arabic word for "sky", it has to do with the last root letter.
What is the correct form of "My Mustafas" in Arabic? If you know the correct answer, you have definitely understood the concept of weak letters in Arabic, i.e, the tricky letters و and ي and Aleph.
Yes, there are one-letter-words in Arabic. You probably know the word for and وَ. But there is more - the imperative.