<h2>Elements With a Set Row Position but No Set Column Position - Sparse</h2>
<div class="container">
  <div class="item a">A</div>
  <div class="item b">B</div>
  <div class="item c">C</div>
  <div class="item d">D</div>
  <div class="item e">E</div>
  <div class="item f">F</div>
  <div class="item g">G</div>
  <div class="item h">H</div>
  <div class="item f">I</div>
</div>

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  margin: 10px auto;
  width: 700px;
  font-family: 'Lato';
  text-align: center;
}

h2 {
  margin: 25px;
  margin-bottom: 50px;
  font-size: 2em;
}

.container {
  display: grid;
  grid-template-columns: 150px 150px 150px 150px;
  grid-gap: 10px;
  font-family: 'Lato';
  text-align: center;
  font-size: 1.4em;
  margin: 40px 30px;
}

.item {
  padding: 40px;
  font-size: 1.5em;
  border: 1px solid black;
}

.b {
  background: violet;
  padding: 100px 0;
  grid-area: 2 / 1 / 4 / 3;
}

.a {
  background: violet;
  grid-area: 1 / 2 / 2 / 3;
}

.c {
  background: orange;
  grid-row-start: 1;
  grid-row-end: 3;
}

.d {
  background: orange;
  grid-row-start: 1;
}