Random Idea English: Compare with or compare to

Saturday, December 4, 2010

Compare with or compare to

In a recent post, I said I was surprised '... that somebody would want to compare language to maths.' Looking back at that sentence later, I thought, 'Hang on. Don't we usually compare something with something, not to something?' But then I remembered Shakespeare's 'Shall I compare thee to a Summer's day?' and the Sinead O'Connor hit 'Nothing compares 2 U' (to you); so I reckoned I was in good company. But what exactly are the rules as to when to use 'with' and when to use 'to'?

Basic rules and a quiz

Full verb - compare with

We use compare with when we examine two things to see what their similarities or differences are:

The police compared the signature on the stolen credit card with that of the original owner.
So, let's compare Sinead O'Connor's version with Prince's. How do they stack up?

We also use compare with when we might use a comparative structure:

Her last album doesn't compare with her previous one. (It's not as good as)
When we compare our new house with our old one, this one has much more space. (It's bigger)

Full verb - compare to

We use compare to when we find a similarity between two things, even though they might really be quite different from each other. This is often metaphorical:

The critics compared his work to that of Martin Amis.
(Oxford)
Scientists sometimes compare the human brain to a computer.
(American Heritage Dictionary)

We could often use the word like in these circumstances. To paraphrase Shakespeare and O'Connor:

Shall I say you are like a Summer's day?
There is nothing (else) like you.

In gerund and present participle clauses

The same distinction would seem to apply as with full verbs, as these two examples from The Guardian show:

Why do critics insist on comparing one artist with another?
= making a comparison between one artist and another
Wild claims comparing YouTube to TV misunderstand what TV is and the reasons why people watch it
= saying YouTube is like TV

In past participle clauses - usually interchangeable

Compared with and compared to are often interchangeable, for example when we are making a general comparison, especially in participle clauses:

This road is quite busy compared with/to yours
(Cambridge Online Dictionary)
Standards in health care have improved enormously compared with/to 40 years ago
(Oxford Advanced Learner's Dictionary)
Compared with/to our old house, this one has more space.

Summary

As a general rule then, it's probably safer to use compare with, except where you are pointing out the similarity of something to something else, where you could use a construction with like instead of compare. Then use compare to.

Quiz - In each group of three sentences, one definitely takes 'to', one definitely takes 'with', and the third can take either (in my judgement). Use the selectors to choose which takes what.

1a.	Your garden is so beautiful compared mine.
1b.	There are far more flowers in it, and it's much better designed, when you compare it mine.
1c.	I hear the local newspaper has compared it the famous garden at Sissinghurst.

2a.	Some people have compared the 2008 crisis the Great Depression of the thirties.
2b.	But if we compare now then, unemployment and inflation have been much lower.
2c.	And the world economic system is very different, compared then.

3a.	The snow has come early this year, compared last year.
3b.	The newspapers are already comparing it that really cold winter of 2005.
3c.	But we don't have enough statistics to compare it 2005 yet. It's only November.

4a.	Jenny is very successful, compared her brother.
4b.	Yes. Compared him, she has a lot more money and a much better job.
4c.	Mum compares her her aunt Susan, you know, the one who started her own business and became a millionaire.