the lower part of the back where it tends to curve in the most.

I will know when it's too late.

It does make sense. I'm just not sure that I'd say it like that if I were to have a conversation with someone.

Hello, How are things going? I hope you and your family are in good health and good spirits. David and I have been doing a lot of sightseeing, but yesterday we stayed at home because we were waiting for plumber to fix the tap and then the weather got so nasty that we simply watched old but kind comedies. Thanks a lot for sending me the photo. It is very kind and thoughtful of you. And again, thanks for your lovely birthday party. How was your trip to Hungary? I hope you don't mind if I send you our photos ( if not it is ok, no worries) best regards to your mum, Dad, and to the grandparents Take care We are looking forward to hearing from you Yours Nada this is how i would say it.

It can also be used in slang, referring to anyone who is not where they are supposed to be.

They are both correct. I use by and through interchangeably.

A source is a place where you obtain something. A resource is something that you need. The source is where the resource comes from. Examples: If I needed water (the resource) I'd go to the well (the source). If I needed money (the resource) I'd go to the bank (the source).

both are right, but the infinitive verbs are not really necessary. You'd here the following more often, rather than the others: He helped me understand the lesson. Can you help us carry these books?