English — Empty 'it'
English sentences need a grammatical subject. When there is no real doer — for weather, time, distance, or a delayed subject — it fills the slot: it's raining, it's five o'clock, it's important to rest.
How it works
Use dummy it as an empty subject for weather (it's raining), time (it's five o'clock), and distance (it's far to the station). Use preparatory it when the real subject is a to-infinitive or a that-clause moved to the end: it's important to rest, it seems that she left.
Examples
| Use | Example |
|---|---|
| Weather | It's raining. / It's cold today. |
| Time / clock | It's five o'clock. / It's Monday. |
| Distance | It's far to the station. / It's two miles from here. |
| Preparatory it + to-infinitive | It's important to rest. / It's easy to learn. |
| Preparatory it + that-clause | It seems that she left. / It's true that he called. |
Good to know
This it is not a translation of a full-verb form: don't drop it (say It's raining, not just Raining or Is raining). It also differs from there is/there are, which introduces existence — say There's a book on the table, not It's a book on the table.