Q:

The confused meaning of sentences from google

I found three strange sentences in Google.
Please explain their meanings to me.

1.I fancy fancy cheeses.
2.I do do it.
3.I'll be in 20 minutes.

A:

"fancy" is both a verb and an adjective.

I like artisanal cheeses.
  I fancy fancy cheeses.

"do" is both a so-called "light" verb and a verb of normal weight.

I do indeed engage in that activity.
  I do do it.

"in" can mean "inside, indoors" and "within a specified time-window", depending on whether it is alone or has a temporal complement:

I will be indoors within 20 minutes.
  I will be in in 20 minutes.

These words, which look identical on the page, are given different intonations and phrasings in spoken English which distinguish them from one another according to their grammatical roles.
Learning a language from  words on a page is far more difficult than learning a language from native speakers of the language as they are speaking it. The written word is a crude approximation of speech.

