Sometimes people think that if they dissolve the compound in water and the solution conducts electricity that the compound will be ionic. This only works part of the time. Lots of molecular compounds with covalent bonds will dissolve in water to produce ions which will make the solution conduct electricity. So this turns out to be an ineffective test for ionic vs covalent compounds. The best example of why this doesn't work in hydrochloric acid. Hydrochloric acid is produced with molecular HCl gas, with covalent bonds, dissolves in water to produce hydrogen ions and chloride ions. There are many other compounds which will produce ions in solution, but which have predominately covalent bonds.
Sometimes people will try to use melting point as an indicator of ionic or covalent bonds. The melting point is determined by intermolecular forces, not the type of bonding within the molecule. In fact the substance with the highest melting point, diamond, is composed of purely covalent bonds.
The bottom line is that the type of bonding is not as clear cut as some teachers (who aren't chemists) try to make it out to be. The simplest approach is to realize that all bonds are essentially the same. They come about because the bonding electrons are attracted to two different nuclei. Because these two different nuclei share the electrons, then all bonds are covalent, but with varying degrees of ionic character.