Verb conjugation of "kosten" in German

My boss offered it to me, so that a few more people at work will have a good level of English and now I really have to kick my own ass (I've started last year and it's not going very well).
They are longer than most examples given by online dictionaries, they resemble actually more to a language study book. Please do the rest of the sample words later today and with 2 pairs each and send them over when you are ready.
It was a short but nice letter from you. I hope that you had a great vacation. I realize that I should practice at least half an hour a day. Vocabulix helps to learn Spanish vocabulary.