The backwards pawn and other pawn problems
The backwards pawn
No, pawns can't go backwards. However, a "backwards" pawn is a pawn that is behind all pawns of the same color on the adjacent files and it can't be advanced safely.
For example, white has a backwards pawn on e3.
The disadvantages to this are that your opponent may be able to "plug" the hole, preventing any pawn movements at all. If it on a half-open file, it is even worse! The pawn is extremely weak and can easily be attacked.
The doubled pawn
A doubled is a pawn in front (or behind) another pawn. These are particularly weak, and can also be made to mate, as in the diagram below.
Not very pretty, and can turn your game into a losing one!
Isolated pawns
No, they aren't practicing social distancing. In fact, they are pretty unhelpful! They are also hard to defend and can create weakness, as it is not supported by other friendly pawns. The squares in front of them can make a useful outpost for a piece like a knight, making them not as bad as the other examples.
See how no pawns are on adjacent files? That is the main weakness.
Pawn structure is very important to chess, so make sure you don't have any pawns like this on the list!
