You all use the punctuation marks “.” and “:” when writing in English. However, in my experience, many German native speakers (and quite possibly other nationals as well) fall into the false-friend trap when actually having to name these symbols. Let me refresh your memory.
The symbol “.”, used at the end of sentences as well as for abbreviations, is called a full stop (British English) or a period (American English). It is not called a point (from the German word “Punkt”), except when used as a decimal separator (decimal point) in numbers. Three points in a row, typically used at the end of sentences or lists, go by the name of ellipsis (not “point, point, point”, as often heard from German native speakers; the formal name in German is “Auslassungszeichen” or “Ellipse”). The name ellipsis goes back to the Greek word for omission, see here. As pointed out in the comments below, “dot, dot, dot” is a common colloquial name for ellipsis among English native speakers.
The name dot is used for the symbol “.” when it appears above letters, for example in the case of umlauts or to denote time derivatives in physics. It is also widely used when pronouncing web and email addresses.
The symbol “:” is called a colon, and certainly not a “double-point” (again a common German false friend originating from the word “Doppelpunkt”).
Finally, the symbol “;” is called a semicolon (“Strichpunkt” in German).