Difference between questions like "у вас ли сыр?" and "есть ли у вас сыр?"

Question

I am a newbie at Russian. To the best of my knowledge, есть is used in questions when possession is being questioned. I was given the following sentences and their translations:

Have you the good sugar? -> у вас ли хороший сахар?

Have you the cheese? -> у вас ли сыр?

So far, so good. But why do the following sentences have есть in them. They don't look(to me) that much different from the above:

Have you good coffee? -> Есть ли у вас хороший кофе?

Have you a new lantern? -> Есть ли у вас новый фонарь?

What am I not seeing that makes all the difference in the latter sentences?

Answer 1

The difference is in emphasis:

1. У вас ли сыр? - Is the cheese with you?
2. Есть ли у вас сыр? - Have you got any cheese?

Ли usually follows the word being questioned:

(1) questions the location of the cheese (with you or somewhere else?)
(2) questions the existence of any cheese with you.

One could also ask:

3. Сыр ли у вас? - Is it cheese that you have?

У вас ли is usually preceded by не:

• Не у вас ли наша собака?
• Не у тебя ли моя ручка?

Keep in mind that ли is rather bookish. In a conversation, you would rather say:

1. Сыр у вас?
2. У вас есть сыр?
3. Это у вас сыр?

Answer 2

I only want to add to (correct and complete) Sergey's answer that questions like "не у вас ли моя ручка" oftentimes imply that the person asking actually already knows that the answer would be yes, like in:

Ты хочешь одолжить у меня чайник? А не у тебя ли мой пылесос, Пётр Николаевич?

Answer 3

У вас ли сыр? - you are asking about certain piece of cheese that you are searching. You know it is at somebody's but not sure at whom.