First of all, its name. While no foreigner has ever heard it and it's not found on restaurant menus, here's the affectionate nickname Italians (yes, waiters, too...) always use for their National Dish: PASTASCIUTTA.

Spaghetti and Meatballs: don't even think about it !

Many people feel that since Americans eat so much pasta, from spaghetti and meatballs to macaroni and cheese, it has become part of our own national heritage, and holds no great surprises. In keeping with this line of thinking, nor should eating pasta in its country of origin present any problems.

To begin with, however, what is thought of by most Americans as spaghetti sauce (with meat) is either referred to as the Spaghetti alla Bolognese sauce, or   ragu. These sauces are not found everywhere in Italy or at every restaurant. In fact, many Italians do not at all like meat sauce on pasta.
Ordering spaghetti and meatballs is likely to draw a blank stare from the waiter and paroxysms of laughter from your Italian companions. This is, for them, a fanciful but quite unheard of combination outside of the United States. If they're on the menu, order polpette (meatballs) as a main course to satisfy your heart's desire and save face.

All you need for spaghetti is a fork

Throughout the world, vast numbers of people have perfected a method of eating spaghetti in what they erroneously believe to be "Italian-style": winding it onto a fork held against a spoon. They will be disheartened to learn that the Italians themselves have yet to adopt this method.

Indeed, throughout Italy, from North to South, Italians wind their spaghetti clockwise onto their forks in the time-honored way -- no spoon attached. And they never seem to end up with a tangled, 3-inch skein of pasta at the end of their forks or noodles and sauce dribbling down their chins...

Practice makes perfect, so perhaps it's not a bad idea to hone your skills with spaghetti, fettucine and tagliatelle at home before going public. A word to the wise: never order any of the above at a business lunch.

Lasagne, lasagnette and lasagne al forno

It must be noted that lasagne are noodles -- a type of noodle. In some regions of Italy, if you order lasagne with any one of a number of sauces, you may be quite shocked to find yourself presented with sheets of pasta the size of notebook paper covered with sauce, when what you really wanted was Lasagne al Forno.
Lasagnette are long, flat noodles with ruffled edges which are boiled, not baked. If you see them served with a tomato/lemon sauce, don’t hesitate!!