English language education for my bilingual child.

[Benjamin1976]

Hi I live with my 4 year old son in Oberstdorf, Germany, does anyone know of any tips I can use to teach my son better English?
His farther is German so he speaks to him German and during the day he goes to Kindergarden were he is just speaking German 80% of the day, I am just getting worried that his English may be lost over time, any hints how I can keep his English up? And also is there a mums English speaking net work in Germany? I'm sure I'm not the only speaking mum in south Germany.