1. Introduction

2. Data and analysis
2.1. Gaia-ESO spectra and analysis
2.2. Sample description
2.3. Selecting the best-quality abundances
2.4. Systematic effects on the abundances
2.5. The solar abundances
2.6. Non-LTE corrections
2.7. Ages for field dwarfs

3. Stellar evolution with open cluster stars

4. Galactic chemical evolution of Na and Al
4.1. Trends with metallicity
4.2. Trends with age
4.3. Trends with galactocentric distance

5. Summary