These sort of things always make me cry ... so sad! Letters written to a WWI soldier by his girlfriend were found in an Army archive in the UK - usually all correspondence is returned to family - somehow these were not. Nothing is known of what became of the girlfriend Harriet Johnson. William Crawford was killed in action in France on February 8 1918, aged 26.
A month earlier, in a letter dated January 9 1918, Miss Johnson wrote: "I always think about you and wish you were here. How I wish this war was over. We are now beginning to know that there is a war as I don't think we realised it at the beginning."
In a letter dated January 29 1917, Miss Johnson wrote: "Well dear Will I am glad that you love me. I want your love because I love you. I often think of you and all that passed between us. But never mind my Dear Will I am not sorry. I only wish that you were here now. I often long for you. I don't know when I shall see you again but I do hope it will very soon."
In another, undated, letter believed to have been sent days before his death, she wrote: "Remember there is always one little girl who will always pray for your safe return." (Link)