Single-letter words
As unusual as it may look, there are numerous words in Czech that consist of just a single letter.
These are (alphabetically): a, i, k, o, s, u, v, z.
This can easily cause confusion, so let's dive in, look at some examples, and figure out how a sentence like the one below can actually work.
A i o tom jsme s ním mluvili. (And we spoke with him about that too. Literally: And even about it with him (we) spoke.)