Identify by airplane characteristics

The Soviet counterpart of the Stearman and Tiger Moth has a relatively small, exposed radial piston engine. Its vertical tail consists of a triangular fixed part (as a sort of dorsal fin) with a larger oval shaped rudder.

Typical for this tandem seat trainer are the large parasol wings, narrow fuselage and large trapezium vertical stabiliser with straight edges. The horizontal stabilisers are attached to the bottom of the latter, making it a marginal cruciform tail. 

This home-built aircraft looks somewhat like a mix between a Stinson Voyager and a Bellanca Decathon. As far as we know only one was built and that is operated on floats. The tick wings with fences near the strut attachment points and the three blade prop maybe what you need to look at to recognise the Punkari Condor.

The PZL I-22 Iryda and Alpha Jet both have high, swept wings, semi-circular air intakes and space between the wings and the nacelles. The differences between them are more subtle: looking at the shape of the air intakes is the most obvious way of keeping them apart.

The most unusual combination of a jet engine on top of the fuselage, underneath the upper wings, and a double T-tail on tail booms, makes the PZL M15 easy to recognise. Additionally, the M15 has two columns between upper and lower wings, which house tanks wing chemicals: the main task was crop dusting. 

The Polish Iskra jet trainer has two rectangular air intakes in front of the wings, just below the roots, leading to a single jet engine in the middle of the fuselage. The exhaust is under the fuselage, well before the cruciform tail.

The PZL TS-8 Bies has inner wings with anhedral and outer wings with dihedral, so inverted gull wings. The retractable main gears are placed at the lowest point. It is powered by a radial piston engines, of which the pistons are not visible, the front of the engine being covered. The tail is a non-swept trapezium with horizontal stabilisers at the base.

In between the many high performance (turbo)prop training aircraft the PZL130 stands out due to its small size. The vertical stabiliser starts almost directly behind the tandem canopy. This fin has a curved leading edge on most versions, extending all the way to the trailing edge.

Under supervision of NASA a DHC-5 Buffalo was modified as Quiet Short-Haul Research Aircraft (QSRA). It has four jet engines on top of the wings, but for the rest it still resembles a Buffalo, including the long main landing attached to the wings. (photo NASA/WikiMedia)

A classic WW-I biplane fighter with four pairs of single struts between them, and a lot of wires. The wing tips are rounded, the vertical fin is triangular with a nearly oval rudder, and horizontal stabilisers with rounded leading edges.