Verb conjugation of "estrechar" in Spanish

I really worry about the health of obese people, especially the ones that I know in person (friends, relatives), because it is well known that overweight have a higher probability of heart attack.
I was a little confused because I recognized the voice and I had booked at Luisa's guest house. She explained me that she was sharing the phone with her neighbor and her neighbor was not honest.
Is there a way that I could test your Spanish and German lessons? Quality is very important to me. Can you send me a lesson electronically (by email or word)? Maybe you have your lesson ready.