Questions & Answers about كلا الاقتراحين مفيدان.
Why do we use كلا here instead of كلتا?
The word كلا is the masculine form of the word both. We use it here because the singular noun اقتراح (suggestion) is masculine. If we were talking about two feminine things, we would use the feminine form كلتا.
Why does الاقتراحين end in ـين (-ayn) when it seems to be part of the subject?
This is because كلا (both) always forces an Idafa (possessive construction). Even though the phrase both suggestions acts as the subject of the sentence, الاقتراحين is technically the second part of the Idafa. Therefore, it must take the genitive case, which for dual nouns is the ـين (-ayn) ending instead of the nominative ـان (-ān).
Why does the adjective مفيدان end with ـان (-ān) instead of matching the ـين (-ayn) ending before it?
The word مفيدان (useful) is the predicate of the sentence, meaning it provides the core information about the subject. Predicates are always in the nominative case, which uses the ـان (-ān) ending for the dual. It does not match الاقتراحين because it is not an adjective directly modifying the noun inside the Idafa; it is the main news of the sentence.
Could I phrase this sentence by putting the noun first?
Yes, you could say الاقتراحان كلاهما مفيدان. In that structure, the two suggestions comes first in the nominative case, and the word for both attaches a pronoun matching them (هما). Both the sentence we are studying and this alternative are common and mean the exact same thing.