English sentences hate starting with heavy or brand-new information. When you want to say that something exists — a delay, a problem, a free table — English uses the little starter 'there': 'There is a delay.' And when the real subject is a long phrase like 'to check the file', English pushes it to the end and puts 'it' in front: 'It is important to check the file.' These two small words carry a huge amount of everyday English: signs, announcements, weather, advice, opinions.

Learners who miss this often translate directly from their first language and say things like 'It has a delay' or 'Is a problem with my order.' Listeners usually understand, but the sentences sound broken, and in writing they look careless. Getting 'there' and 'it' right instantly makes your English sound settled and natural.

Existential 'there' announces that something exists or happens. The form is: There + be + noun (+ place/time). 'There is a pharmacy near the station.' 'There were two messages for you.' The verb 'be' agrees with the noun that follows it: 'There IS a problem' but 'There ARE problems.' You can use other tenses too: 'There will be a meeting at ten', 'There has been an accident.' Questions and negatives work through 'be': 'Is there any milk left?' 'There isn't enough time.'

Notice what 'there' is doing: it is an empty starter, not a place word. In 'There is a park nearby', 'there' does not mean 'in that place' — it just opens the sentence so the new noun ('a park') can arrive after the verb, where English likes new information.

Anticipatory 'it' solves a different problem. Suppose your real subject is long: 'To check the file before sending is important.' Grammatically fine, but front-heavy. English prefers: 'It is important to check the file before sending.' The 'it' is a placeholder; the true subject waits at the end. The same trick works with 'that' clauses ('It is strange that nobody called') and with '-ing' forms ('It was fun meeting your parents'). Common frames: It + be + adjective + to/that..., and It + takes/costs/seems/turns out...

'It' also covers weather, time, and distance, where no real subject exists: 'It is raining', 'It is half past nine', 'It is ten kilometers to the coast.' These are fixed uses — never 'There is raining.'

So how do you choose? Ask what your sentence does. Announcing that something EXISTS or is present? Use 'there' + be + noun: 'There is a delay.' Evaluating or commenting, with the real content coming later as to-do or that-clause? Use 'it': 'It is important to check the file.' A quick test: if you can put a noun right after 'be', you probably want 'there'; if an adjective or evaluation comes after 'be', you probably want 'it'.

1. 1. There is a long queue at the bakery this morning.

   'There is' introduces something that exists; the noun follows 'be'.

2. 2. There are two direct trains to the airport every hour.

   Plural noun 'trains', so the verb becomes 'are'.

3. 3. Is there a cash machine inside the mall?

   In questions, 'be' moves before 'there'.

4. 4. There isn't any parking on this street after five.

   Negative existence: 'There isn't any...' with an uncountable noun.

5. 5. There was a mistake on my electricity bill.

   Past existence: 'There was' for one singular thing.

6. 6. There will be a short break after the presentation.

   'There' works with future forms too: 'There will be...'.

7. 7. There has been a change to tomorrow's schedule.

   Present perfect with 'there': 'There has been' for recent news.

8. 8. It is easy to get lost in the old town.

   'It' is a placeholder; the real subject is 'to get lost...'.

9. 9. It was kind of you to carry my suitcase.

   'It was + adjective + of you + to...' evaluates a person's action.

10. 10. It seems that the shop opens later on Sundays.

    'It seems that...' pushes a whole clause to the end.

11. 11. It takes twenty minutes to walk to the clinic.

    'It takes + time + to...' is a fixed frame for duration.

12. 12. It is raining hard, so there is water everywhere.

    Weather 'it' and existential 'there' living in one sentence.

13. 13. Is it necessary to book a table on weekdays?

    Anticipatory 'it' in a question: 'Is it + adjective + to...?'

14. 14. It surprised everyone that the tickets sold out so fast.

    The 'that' clause is the real subject, parked at the end.

15. 15. There is no reason to worry about the results.

    'There is no + noun' is a natural way to deny existence.

The classic error is using 'it has' or plain 'it is' to announce existence: 'It has a delay', 'It is a problem with my order.' English does not use 'have' or bare 'it' this way. When something exists, start with 'there': 'There is a delay.' 'There is a problem with my order.' Reserve 'It is a...' for identifying something you both already see: 'What's that noise? — It is a fire alarm.'

The mirror-image error is dropping the starter completely: 'Is a delay on line two.' English statements need a subject before the verb, even an empty one. Say 'There is a delay on line two.' The same goes for evaluations: 'Is important to check the file' must become 'It is important to check the file.' If your sentence begins with 'Is' but is not a question, a 'there' or 'it' is missing.

Finally, watch agreement and mixing. Learners say 'There is many options' — but the noun after 'be' controls the verb: 'There are many options.' And do not let 'there' invade 'it' territory: weather and time always take 'it' ('It is windy today'), never 'There is windy'.

• Something exists? Start with 'There is/are + noun'.
• Long subject (to-do or that-clause)? Start with 'It is + adjective'.
• 'It has a problem' about a situation is wrong — say 'There is a problem'.
• The noun after 'there + be' decides is/are, was/were.
• Weather, time, and distance always take 'it': 'It's cold', 'It's 9 pm'.
• A statement starting with bare 'Is...' is missing its 'there' or 'it'.