One should not say “Shalom Alecheim” to another person before praying in the morning. This is because “Shalom” is a name of G-d and it is not proper to give honor to another person with this name before giving honor to G-d (through prayer). A person can say “Good morning” because this does not use the name of G-d.
4. Be kind to yourself. Speaking badly even about yourself is unethical.
הלכות שמירת הלשון 