OK, let’s take a look at a few prepositions, and a really easy way to remember how to use them.

- to / from

In task 1, you will use “to” if you are talking about *change*. So, if something goes up or down, we use “to”. Look at the example:

The number of people rose **to** 800,000 in 2011.

So, we use “to” for changes, and we use it to describe the second number – the number at the *end* of the increase / decrease.

We also use “to” with “from” – like *from 400,000 to 800,000 – *again, we are talking about the end number. If we want to talk about the start number, we use

**“from”**.

2. by

We use “by” similarly to “to”, so when we talk about change. This time, however, we are thinking about the *difference* between point A and point B. Here’s another example:

Number of people, 2001 = 55

Number of people, 2005 = 60

The number of people rose **by** 5 from 2001 to 2005.

So, we also use “by” for changes as well, but to talk about difference.

3. at

We use “at” to talk about numbers that *haven’t* changed over time. Look at this example:

The number remained steady **at** 25 for about five years.

So, “at” is used in the opposite situation to “to”.

4. with

We use “with” when we just want to talk about **one** number, at **one** time, with no changes. Here’s an example:

The highest number was in the 16-25 age group, **with** 500,000.

**Conclusion**

So, here’s the simple way to remember:

to – change, second number

from – change, first number

by – change, difference between first and last

at – no change over time

with – one number, no movement in time

Good luck!

Simon