。
I miss you.
Literal
Meet-cannot-[and-て] lonely.
Japanese has no direct verb for 'to miss someone.' Instead, the standard expression is 会えなくて + 寂しい/淋しい — 'lonely because/from being unable to meet.' 会えない is the potential negative of 会う. 淋しい is a less-common written variant of 寂しい with the same meaning ('lonely, sad'). The なくて form connects the cause to the resulting feeling.