The main function of the expression il y a is to describe factually things in the space.
Dans la cuisine, il y a : un évier, un four, un frigo… (In the kitchen, there is : a sink, an oven, a fridge…)Il y a is generally placed at the beginning of a sentence, followed by what you want to describe. This can be :
• a noun (with an article)
Il y a une montagne. (there is a mountain)• a nominal group
Il y a deux grandes montagnes enneigée. ( There are two big snowy mountains)• a pronoun
Il y a nous. (There are us)So il y a is the equivalent of there is / there are. Notice that it doesn't vary, even if there are many things to describe.
The verb avoir following il y can be conjugated at other tenses than indicative present (avait, aura, etc.).
Il y aura un orage. (There will be a thunderstorm)Il y avait quelqu'un. (There was someone)Il y a eu un problème. (There was/ has been an issue)The question qu'est-ce qu'il y a ? is a daily-life sentence to ask if there is a problem (= What is going on ?). If someone asks this question, they probably expect a detailed answer about your state of mind or an issue you have met.
Tu as l'air stressée, qu'est-ce qu'il y a ? (You seem stressed, what is going on ?) - Je passe un examen important mais je ne me sens pas prête. (I am taking an important exam but I am not feeling ready.)> the answer is detailed and addresses the substance of the problem. It is not a factual description.If someone asks qu'est-ce qu'il y a. You can answer by repeating the expression il y a at the beginning of the sentence. But be careful ! Due to the repetition of the term, your response will sound like a reproach, with an annoyed tone.
Ça ne va pas ma chérie ? Qu'est-ce qu'il y a ? (Are you alright darling ? What is going on ?)- Il y a que c'est notre anniversaire de mariage et que tu as encore oublié. (It's our wedding anniversary and you forgot again.)> Il y a que clearly indicates a reproach in the answer.Note that il y a is followed by the small buffer word que. Grammatically, the phrase il y a has to be followed by the coordination conjunction que before a subordinate phrase.
When il y a is followed by a time adverb or a time unit, this indicates a moment in the past.
Il y a bien longtemps, dans une galaxie lointaine… (A long time ago in a galaxy far, far away.…)Il y a un an, Il y a un siècle, Il y a une éternité. (A year ago, a century ago, an eternity ago.)This is the opposite of dans, that indicates a moment in the future.
Dans un an (In one year)Dans longtemps (In a long time)Dans deux minutes (In two minutes)