The obvious way is to use a pH meter! If not available, then you could use Universal Indicator strips.
Universal indicator strip dipped into each substance will change colour to either red (strong acid), orangy-yellow (weak acid), green (neutral), blue (weak base) or purple (strong base).
But the quickest and most simple way to assess them is to use a pH meter, which is very common in laboratories. The meter will give a numerical reading of pH, and from this you can categorize the samples. Strong acid (pH <3), weak acid (roughly pH 3 to 6), neutral (pH 7), weak base (roughly pH 8 to 11) and strong base (pH > 11).