Do you listen to yourself when talking to another co-worker? Are you formal and stiff? Do you avoid any pleasantries and jump right to the reason for your conversation? If you do (and you know who you are), you are sending signals that you are standoffish, causing others to avoid working with you or cooperating.
To improve try the following;
Say hello. Simple yet powerful and it will encourage your colleague to welcome you.
Avoid speaking in technical terms or jargon. These terms can be unfamiliar to others and the will tune you out if they do not understand you.
Relax. Take a deep breath and remind yourself to slow down before the conversation.
Make eye contact. Look directly at the person you are speaking with.
Allow for a response. Do not pop in and then run off when you have your answer, ask if there are any questions and ask for input.
Simple steps that will leave your co-worker or direct report feeling valued and you on your way to a more productive day.