Hi there,
I took my car for it's ITV in December and like you my Spanish was not great. However, the test is really straightforward. You stay in the car and just drive it forward through the test station when told. The tester will tell you when to brake, indicate, put lights on etc and as you will have discovered the spanish has actions to help you understand anything. My tester spoke no english at all and I still managed to understand. I would imagine on the coast you have more chance of english speaking testers. If in doubt, watch the car in front so you have an idea of what to expect when it's your turn. Do not be put off when they ask you to drive forward but help you steer the car - it's common practice, not because they think you are a bad driver!! Good Luck