Cut an eighth in half and you get a sixteenth note. The standard count for a beat full of sixteenths is "1 e & a" — one syllable per sixteenth, evenly spaced. The e and the a are the two new pulses that didn't exist when you were just counting eighths.
Sixteenth notes are where funk, R&B, and most modern drumming live. Even when not every sixteenth is played, the grid is what your time is locked to.
Exercises
1 — Straight Sixteenths
Sixteen even strokes. Count 1 e & a · 2 e & a · 3 e & a · 4 e & a out loud. Every syllable is a stroke.
2 — Eighth + Two Sixteenths
On every beat: a single eighth followed by two sixteenths. Counts per beat: 1 & a · 2 & a · 3 & a · 4 & a. The e is silent — feel it land between the 1 and the &.
3 — Two Sixteenths + Eighth
Mirror image of the previous exercise: two sixteenths first, then an eighth. Per beat: 1 e & · 2 e & · 3 e & · 4 e &. The a is now the silent one.
4 — The 'e a' Pattern
A mixed-density bar combining the patterns from exercises 1–3. Don't memorize the rhythm shape — read it by counting through each beat. 1 & a · 2 & a · 3 e & a · 4 & a.