надо
где писать the, а где нет

Learned / has been learning
are discussing / have been discussing
is working / has he worked a long? / he has been working
teaches / has been teaching
know / have you known  / have known

Честно говоря, меня немного поставила в тупик эта часть: He (to work) long?
Возможно ты что-то пропустила там. По логике должен был быть вопрос "Как долго он уже работает" - "How long has he worked?" Но на этот вопрос не может быть ответа, который следует дальше (-Yes, he...) Так что здесь возможен косяк. Остальное, надеюсь, сделал правильно))

Dear friend, best wishes, I am writing to you. I received your letter, for which I thank you very much. I still spend a vacation in the countryside, visiting grandparents. I love it here, so stay here until the end of the summer. I have made many friends here. We are with them to have fun: play soccer, go swimming in the river, in the woods to pick berries. Guys - good, catchy. I help my grandmother. She has a small farm: chickens, rabbits and goats. With a couple of times a grandfather go fishing. Got up very early, when still only just beginning to get light when the grass is still lying under the weight of the morning dew. Here caught perch, bream, roach. Grandfather I have experienced fisherman, so without a catch, we never returned. From the first fishing have always meets cat Vaska. Oh, and he is a lover of fish to eat! But my friend, doggie, do not eat fish, and fishing accompanies us. Is with us until the end. Well, just the third angler! The weather is a real summer. Many sunny days in the gardens of brewing a good harvest. And what nature here! You leave in the morning on the porch at home - and you are met by a green sea of ​​trees, shrubs, various paint colors, the singing of birds. Here - it's not you in the city. Here the whole day is rich in new discoveries, new research. I also went to the village library - read a lot of pieces that we were asked to extracurricular reading. But honestly, read boring when everyone around you is full of life. I read just before bedtime, and even then not every day. Sometimes the day was so tired that my eyes just stick themselves. The days go by very quickly. Coming to school, but to be honest, it still would not be desirable. I would like, however, to see you and the other guys. Talked b. Write - How to relax you, what do you know about our. Tell them hello if you see. Write. I will be glad. Goodbye. Your friend