what was happening
¿Cómo puede ser que nadie viera lo que estaba pasando?
How could no one have seen what was happening?
No podía decirle a Tom lo que estaba pasando.
I couldn't tell Tom what was going on.
Ella intentó ocultar lo que estaba pasando realmente.
She tried to hide what was really happening.
No se enteró de lo que estaba pasando.
He/She had no idea what was going on.
Realmente no entendí lo que estaba pasando.
I really didn’t understand what was happening.
No creía que nadie se diera cuenta de lo que estaba pasando.
I didn’t think anyone would notice what was going on.
Tomás no se dio cuenta de lo que estaba pasando.
Tomás didn't realize what was happening.
Fingí como si no supiera lo que estaba pasando.
I pretended I didn't know what was going on.
Tom no sabía nada acerca de lo que estaba pasando.
Tom had no idea what was going on.