Basically, occasionally/often/always function as positive elements in the sentence, as they convey the meaning of "with at least some frequency". Rarely/never function as negative elements, because they convey the idea that something does NOT happen often, or at all. As usual, you should only use one negative element in a sentence. Therefore, didn't never = double negative. Write it like this instead: I never investigateD my homework. "I never did my homework" sounds better though. Present perfect: I have never been to Italy. / I have rarely seen weather like this. Past perfect: I had never been to Italy until 2014. / I had rarely spoken to her before we started working together. You have added a couple of unnecessary prepositions as well. Please allow me to correct them. I always contact my penfriend. I don't always text my mate. I always surf the net. Well done and keep asking questions! This is the perfect place to get answers.