One period. The period in etc. also functions as the period for the end of the sentence.
If a sentence ends with an abbreviated word then only one period (full stop) is used.
Actually it should look like this (cars, airplanes, trains, etc.). But if the sentence ends with an abbreviation, the single period will serve to end the sentence, as in cars, airplanes, trains, etc. You do not use double periods. You can, however, use a question mark or exclamation point after a period that ends a sentence. Were you talking about cars, airplanes, trains, etc.? If this looks unusual, it is because abbreviations, such as etc., are generally avoided at the ends of sentences.
This sentence is an example of correct usage (and you can tell your friends, enemies, etc.).
No you do not
Three periods at the end of a sentence is called an ellipses. It means that the statement continues as understood by the writer and reader. Usually the term etc is used.
No one period is sufficient.
Et cetera is abbreviated to etc. No second period is needed but you will sometimes find one anyway.
Punctuate means to insert figures like comma, period, exclamation marks etc. in a sentence.
Etc. is an abbreviation of et cetera or etcetera. Etc., not e.t.c., is the correct grammatical abbreviation. I hope your periods etc. stop fighting each other.
If it is ten and over then you spell it. (ten, eleven, twelve...etc.)
Yes, it can. "Neither ABC nor XYZ can/should/are/etc. ...".
An answer that basically almost never ends. Haha, likeee Bob was good, and he was smart, and he liked red, and he was cute, and he knew how to tie his shoes, and he was stupid, and he was ... etc. LOLOL