"I would have studied English if I had gone to school, but I have/had to work instead." Are both "have" and "had" correct tenses in this sentence ?
As the working, i.e. going out to work took place at the time s/he would have liked to be at school, the speaker is talking about the past, so 'had to' is the natural one to choose.
Context is always important; labelling is rarely important.