Substitute

The speaker addresses Sam, who has spent a long time waiting for a woman who may not return. The speaker says they have been waiting too, offering affection and support in place of the absent partner. The mood is caring and hopeful, but also a little impatient: the speaker wants Sam to stop waiting and notice the possibility of a new relationship.

“Substitute” means someone who takes another person’s place, so the speaker presents themself as a replacement partner. Sam’s habit of sitting by the window and hoping to see the woman shows how focused he is on her return. The speaker’s repeated offer to be there “whenever” Sam needs them suggests dependable comfort, though it also makes the offer sound conditional on the woman not coming back.

The song can be heard as a sincere offer of love from someone who understands loneliness. At the same time, the speaker may be taking advantage of Sam’s disappointment, since they are waiting for their chance and urge him to forget the woman. The lyrics do not tell us whether Sam welcomes this attention or whether the woman will return, so the ending remains open.