Just like 2/4, the time signature 4/4 usually (but not always!) tells us that the macrobeats (DU) will be represented by a quarter note, and that microbeats (DU DE) will be represented by paired eighth notes.
Rhythm Cells in 4/4
Reading Rhythm Patterns in 4/4
We can read the exact same patterns we read in 2/4, except this time, we will notate them in 4/4. This is as simple as removing the bar line, and reading four macrobeats in a measure instead of two. Sometimes, if there are two pairs of microbeats, all four microbeats are beamed together.