Hey Adam!  This is known as slicing in FL Studio.

In the Playlist’s top tool bar, select the knife icon (looks like an exacto knife), then hold LEFT-CLICK to slice where you want.

You will find by itself, you are not able to slice audio in FL Studio with fine slices with just LEFT-CLICK however..

To get more control over audio slices in FL Studio, there’s two approaches:

1. Adjust the Playlist snap to (none)  [the magnet icon.. you’ll see “Main”, “Line”, “Cell”.. look for (none)].
2. Hold the ALT + SHIFT (the fastest way)

So to recap.

Load your audio file into the Playlist.

Select the slice icon in the top toolbar in the FL Studio Playlist.

Use ALT + SHIFT + LEFT CLICK to fine-tune the slice exactly where you want.

To move the audio, you will see it “snaps to grid”.  To break free from the FL Studio Playlist snap, you can either do (none), or go back to the paint brush or pencil, and hold ALT + LEFT CLICK.

Let me know if you’re confused at all!

(After slicing, you have to go back to the brush to move the audio, and ALT breaks free from the snap).