Let's look at the word family for 'compare'. Remember that we are looking at usage, not meaning (I'm sure you know the meaning of these words).
- The graph compares the number of males and females...
- 10% of males were unemployed, compared to only 8% of females.
- The unemployment rate was high in 2008 compared with previous years.
- The unemployment rate was high in 2008 in comparison with...
- By/in comparison, the unemployment rate in 2008 increased to...
- Figures for the USA were comparable with/to those for the UK.
- The figure for females was comparatively low, at only 8%.
You've probably noticed that this word family is really useful for writing task 1.
PS. Thanks to Martin for sharing this online dictionary. The 'usage notes' at the bottom of the page are especially helpful.