What is the difference between il y a and il est in French?

Both translate as 'there is' in some contexts, but they cover different ground. Il y a (literally 'it there has') is the all-purpose 'there is / there are' for existence - 'il y a un chat dans le jardin' (there's a cat in the garden), 'il y a trois enfants' (there are three children). Il est is used only for telling time - 'il est trois heures' (it's three o'clock) - and in higher-tier constructions like 'il est difficile de...' (it's difficult to...). For everyday 'there is / are', il y a is what you want.

How does il faut work in French?

Il faut is an impersonal verb meaning 'it is necessary' or 'one must'. It can be followed by a noun ('il faut du pain' = bread is needed) or by an infinitive ('il faut partir' = one must leave / we have to leave). The il has no real referent - it's grammatical only. There's no English equivalent that's both as compact and as universal; closest is 'gotta' or 'need to'. Past form: il fallait (it was necessary). Future: il faudra (it will be necessary). Conditional: il faudrait (it would be necessary / one should).

French Impersonal Verbs

Impersonal verbs in French are ones where the subject il has no real referent. There is no "he" or "it" doing anything. The il is a grammatical placeholder, the same way English uses "there" or "it" in "there is a cat" or "it's raining".

il y a: there is / there are

The all-purpose existence marker. Same form for singular and plural.

Il y a un chat dans le jardin. (There's a cat in the garden.)
Il y a trois enfants. (There are three children.)
Il y a un probleme. (There's a problem.)
Il y a beaucoup de monde. (There are a lot of people.)

The structure parses as il y a = "it there has", but the English equivalent is just "there is / are".

Tense forms:

Tense	Form	Meaning
Present	il y a	there is / are
Imparfait	il y avait	there was / were
Passe compose	il y a eu	there has / had been
Futur	il y aura	there will be
Conditionnel	il y aurait	there would be

Negation: il n'y a pas. Il n'y a pas de pain (there's no bread). The article-becomes-de rule applies here as everywhere.

Question: Y a-t-il un probleme? (Is there a problem?) - formal, with inversion. Or Est-ce qu'il y a un probleme? - neutral. Or Il y a un probleme? - casual.

il faut: one must / it's necessary

Expresses necessity. Followed by a noun, an infinitive, or que + subjunctive (Higher-tier).

With an infinitive:

Il faut partir. (We have to leave / one must leave.)
Il faut manger. (One must eat.)
Il faut etre patient. (You have to be patient.)
Il ne faut pas oublier. (You mustn't forget.)

With a noun (a need for something):

Il faut du pain. (Bread is needed.)
Il faut du temps. (Time is needed.)
Il me faut un stylo. (I need a pen. - me adds the person)

The construction is impersonal - the il refers to nothing. The subject of the infinitive is implied by context.

Tense forms:

Tense	Form	Meaning
Present	il faut	one must
Imparfait	il fallait	one had to / it was necessary
Passe compose	il a fallu	one had to
Futur	il faudra	one will have to
Conditionnel	il faudrait	one should / would have to

il fait + weather

The default construction for weather. Il fait + adjective covers most of it.

Il fait beau. (The weather is nice.)
Il fait chaud. (It's hot.)
Il fait froid. (It's cold.)
Il fait mauvais. (The weather is bad.)
Il fait jour. (It's daylight.)
Il fait nuit. (It's nighttime.)

For weather as a verb (the active phenomenon), French uses il + weather verb:

Il pleut. (It's raining.)
Il neige. (It's snowing.)
Il gele. (It's freezing.)

Or il y a + noun:

Il y a du soleil. (It's sunny.)
Il y a du vent. (It's windy.)
Il y a du brouillard. (It's foggy.)

All three patterns coexist. Foundation tier wants you confident with il fait + adj and il pleut / il neige at a minimum.

il est + time

Time-telling uses il est (not il y a, not il fait).

Il est trois heures. (It's three o'clock.)
Il est midi. (It's noon.)
Il est minuit et demi. (It's half past midnight.)
Quelle heure est-il? (What time is it?)

The same il est is used in some Higher-tier impersonal constructions (il est difficile de..., il est interdit de...), but for Foundation tier it's mostly the time-telling verb.

il manque, il reste (briefly)

Two more impersonal verbs worth recognising:

Il manque trois personnes. (Three people are missing.)
Il reste deux gateaux. (There are two cakes left.)

The il is grammatical; the real subject (the missing people, the remaining cakes) comes after the verb. These are Higher-tier on the AQA list but show up at Foundation level in passive listening.

Worked examples

Il y a beaucoup de monde au marche ce matin. (There are a lot of people at the market this morning.)
Hier, il y avait un concert dans le parc. (Yesterday there was a concert in the park.)
Il faut partir maintenant si on veut arriver a l'heure. (We have to leave now if we want to arrive on time.)
Il ne faut pas oublier ton passeport. (You mustn't forget your passport.)
Il fait beau, mais il y a du vent. (The weather is nice, but it's windy.)
Hier, il a plu toute la journee. (Yesterday it rained all day.)
Il est cinq heures et demie. (It's half past five.)

Common mistakes English speakers make

Using il y a for time and il fait for existence: time wants il est, existence wants il y a, weather wants il fait or il pleut. They're not interchangeable. Forgetting the article-becomes-de rule under negation: il n'y a pas du pain is wrong, it's il n'y a pas de pain. And translating "I have to" with j'ai a - the French construction is il faut que je... or just je dois... (with devoir).