I have been teaching not just English, but Math and Science as well. Though I am good at Math, I must be constantly learning in order to explain things better. As for Science, I know not much, so I just do lessons for my son and another kid without compensation. Much remains for me to learn about English and Math. With Science, I sometimes don't fully understand what I have studied. It is challenging and frustrating at times, but it merits my good efforts. I don't understand the purpose of "This time" "I know not much" is a little bit more poetic than "I don't know much". "I don't understand what I have learned" is a little confusing because you couldn't have learned it if you didn't understand it. Here are your actual mistakes: "a lot" is not a preposition. It cannot take a noun as an object. Thus "a lot English" makes no sense You are "frustrated". Your efforts are not "frustrated". To use "frustrated" correctly, you would need to say "It is challenging and I feel frustrated at times..."

This time, I have been teaching, not just English, but also Math and Science. I am good at Math yet I still have to learn more to teach better. As for Science, I don't know much so I just teach my son and another kid for free. I have to learn a lot of English for both Math and Science and sometimes I don't understand what I have learnt. It is challenging and frustrating at times but it worthwhile.

This time, I have been teaching not just English but also Math and Science. I am good at Math yet I still have to learn sometimes to teach better. As for Science, I don't know much so I just teach my son and an other kid for free. I have to learn a lot both English, Math and Science and sometimes I don't understand what I have learnt. It is challenging and frustrated at times but it is my good efforts.

This time, I have been teaching not just English but also Maths (British English) and Science. I am good at Maths yet I still have to learn sometimes to teach better. As for Science, I don't know much so I just teach my son and another kid for free. I have to learn a lot both in English, Maths and Science and sometimes I don't understand what I have learnt. It is challenging and frustrating at times but I make good effort.