1.Commands with the Low Fall (preceded or not preceded by the Falling Head or the High (Medium) Level Head) are very powerful, intense, serious and strong. The speaker appears to take it for granted that his words will be heeded, that he will be obeyed, eg: Try the other key. (H. L. H.) Come and have dinner with Tom. (F. H.)
2..Commands with the High Fall (associated with the same types of heads) seem to suggest a course of action rather than to give an order; the speaker does not seem to be worrying whether he will be obeyed or not, eg: Put some more milk in it. (H. L. H.)
3..Short commands pronounced with the Low Fall alone sound unemotional, calm, controlled, often cold, eg: Take it. Stop it.
Exclamations
1.Exclamations are very common with the High Fall (either with no head or with some commonly used heads), eg: Magnificent. (No Head) What an extraordinary piece of Muck. (H. L. H.)
2.For exclamations which refer to something not very exciting or unexpected the low falling tone is used (either with no head or with the heads of common usage), eg: That's nice.(M.L.H.) Wonderful. (No Head).