NGO to collaborate in HCMC (Ho Chi Minh City)

Hi all!

I´ll be moving soon to HCMC to work during Protected content , i would like to know if there is any NGO where i could collaborate as volunteer on the evenings or weekends, not just donating but doing some real work. I´m a Spanish (could give some spanish lessons) industrial engineer (if some NGO is related with this field).

Thx in advance!
Cheers!!