English present tense auxillary verbs

From where do they come? I don't mean can, should, must, and similar words, I mean to be and to do. When I started studying German, I found that they don't use them. I was thinking that they come from Celtic languages.

You do use it in German, only not as much as the english do... Don't know if it originated from the Celtic languages, but the english language has had very little Celtic influence, so not very likely.

"Some languages use "be" for the perfect forms of some or all verbs, instead of "have". French, German, and Dutch use it for verbs of motion and becoming, and (in German and Dutch) for "to be" itself, as does Italian. The use of auxiliaries is one variation among Romance languages."

I see. I knew about motion verbs using to be in the past perfect tense instead of to have in German and French. But isn't the perfect tense used to indicate the past?