I gave you an rather lengthy answer to your other post on the Nursing Student Assistance Forum.
Activity Intolerance related to shortness of breath as displayed while performing ADL's.
"Shortness of breath as displayed while performing ADL's" is a symptom and cannot be used as a related factor for this diagnosis.
Deficient Knowledge related to inability to understand accents of foreign doctors as expressed by patient.
Look at the defining characteristics and related factors for this diagnoses and see if what you have listed here meets any of those criteria. Not being able to understand what someone says because you can't understand their accent is NOT a knowledge deficit.
Risk for Infection related to lung tissue damage and steroid use.
The "lung tissue damage" is OK for a risk factor. However, steroid use is causing what? Immunosuppression? Then, you need to list "immunosuppression" as the related factor and not the steroid use. Steroid use does not cause a risk for infection in everyone. Only when it has gone to the point of causing immunosuppression does it become an infection risk.
You said in your other post that you have two nursing diagnosis books. You need to be using the information under each nursing diagnosis for reference. Think of these books as "dictionaries" to help you with using nursing diagnoses so you get the definitions, related factors and symptoms right.