للأسف، مجفف الشعر والخزنة ليسا في الجناح.

للأسف means unfortunately or regrettably.

It is an idiomatic expression made from:

• لِـ = a preposition
• الأسف = regret / sorrow

So the literal structure is something like with regret, but in natural English it is simply unfortunately.

In pronunciation, لِ + ال becomes لِل here, so it is said roughly as lil-ʾasaf.

This is an iḍāfa construction, often called a possessive or genitive construction.

It is made of:

• مجفف = dryer
• الشعر = the hair

So literally it means dryer of the hair.

Arabic often uses this kind of noun-plus-noun structure where English uses a noun modifier:

• hair dryer
• literally in Arabic: dryer of the hair

So مجفف الشعر is the normal way to say hair dryer.

Because in an iḍāfa, the first noun normally does not take الـ.

Instead, the definiteness of the whole phrase is determined by the second noun. Since الشعر is definite, مجفف الشعر is also definite as a whole.

So:

• مجفف الشعر = the hair dryer
• even though مجفف by itself does not have الـ

This is a very common Arabic pattern.

ليسا is the dual masculine form of ليس.

The sentence has two things as its subject:

• مجفف الشعر
• الخزنة

Because there are exactly two items, Arabic uses the dual form:

• ليسا = the two are not

If there were only one masculine noun, you would use ليس. If there were only one feminine noun, you would use ليست.

When two nouns are joined together and they are of mixed gender, Arabic normally defaults to masculine agreement.

So here:

• مجفف الشعر is masculine
• الخزنة is feminine

Together, they take masculine dual agreement:

• ليسا

If both nouns were feminine, you would expect:

• ليستا

That rule mainly applies to non-human plurals, not to the dual.

For example, with a non-human plural, Arabic often uses feminine singular agreement. But here we do not have a plural noun. We have two separate items, so dual agreement is used.

That is why ليسا is correct here.

So the key point is:

• plural non-human often behaves differently
• dual still takes normal dual agreement

In the present tense, Arabic usually does not use a separate word for is/are in this kind of sentence.

So the positive version would be:

• مجفف الشعر والخزنة في الجناح
• The hair dryer and the safe are in the suite

To make it negative, Arabic often uses ليس and its forms:

• ليسا في الجناح
• are not in the suite

So ليسا is doing the job of are not.

Yes, جناح literally means wing.

But in hotel vocabulary, الجناح also means suite. English does the same thing historically: a suite can be a special section or set of rooms.

So in this sentence:

• في الجناح = in the suite

This is a very natural hotel-context meaning.

If you are studying case, the main relationships are:

• مجفف is part of the subject, so it is in the nominative
• الشعر is the second term of an iḍāfa, so it is in the genitive
• الخزنة is also part of the subject, so it is in the nominative
• الجناح comes after في, so it is in the genitive

So the structure is roughly:

• subject: مجفف الشعر والخزنة
• negative copula: ليسا
• location phrase: في الجناح