Maybe you are referring to the apostrophe such as in I'm or I'll. Here it can mean that a contraction was made. I am = I'm. It also has some other meanings which appear in another thread.
Could you give us an example?
The Tilde is the mark (~ or sometimes ´ ) that is normally put over a letter in a Spanish word to show where to put an accent or to crea
~ the tilde ~ also has some usages in computer file names. I think it may be used to abbreviate long file names so that certain operating systems, which are incapable of understanding long file names, can understand them.
Thanks Ryan. I didn't know that the ~ also meant an approximate number. You learn something every day. Maybe they taught me this at school but since I never used the symbol, I forgot about it.
That's the way it is for English learners too. If you don't use it, you lose it.