Learn Arabic (Modern Standard): السؤال العاشر صعب.

In Arabic, ordinal numbers like "first", "second", or "tenth" act just like adjectives. Because the ordinal here is describing a specific noun—"the question" (السؤال)—which has the definite article "ال", the word for "tenth" must also take "ال" to match it perfectly.

How is the word for "tenth" (عاشر) formed from the regular number ten (عشرة)?

Ordinal numbers from 2 to 10 are built by putting the root letters of the number into a specific sound pattern. If you drop the ending from the normal number ten (عشرة / 'ashara), you get the root letters for 1-0. To make it "tenth", you stretch the first vowel into a long "aa" sound: عاشر ('aashir). You will hear this same long "a" sound in other ordinals like ثالث (third) and رابع (fourth).

Why doesn't "صعب" (hard) have "ال" (al-) like the first two words?

This missing "ال" is exactly how Arabic builds an "is" sentence! The first two words (السؤال العاشر) both have "ال", meaning "the tenth question". Because صعب (hard) does not have "ال", it acts as the predicate (the new information). This contrast between definite and indefinite words creates the invisible "is", giving us "The tenth question is hard."

Are the words in this sentence masculine or feminine?