僕はこれ以上歩けないよ。

I; me; you; manservant

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

this (indicating an item near the speaker, the action of the speaker, or the current topic); this person (usu. indicating someone in one's in-group); now; here; I (me); certainly

not less than; ... and more; ... and upwards; beyond ... (e.g. one's means); further (e.g. nothing further to say); more than ... (e.g. cannot pay more than that); above-mentioned; foregoing; since ...; seeing that ...; this is all; that is the end; the end

indicates certainty, emphasis, contempt, request, etc.; used when calling out to someone; used to catch one's breath or get someone's attention; yo!