Accelerating

I have a Suzuki Ignis which is not among the choices given for model. I bought it in Italy which is where I live. It was working well until my son, who got his license about a year ago, started using it. Lately when I accelerate it lags or doesn’t really respond quickly. It is as if the accelerator and the engine are not in synch. It is similar to the sensation of trying to draw a deep breath but not being able to actually get it. My car is short of breath! Any ideas as to what it might be?

Dirty air filter?

I will ask…I did have what in Italy they call a Tagliando which means the equivalent of an annual check up. it was done in January so I would have thought they would have caught any dirty air filters. The car as 30,000 miles on it and is from 2007 and has had its annual check up every year. do you still think it might be a dirty air filter? perhaps they don’t change these during the check up. Perhaps what I should be calling it is a tune up- not sure.