The adjective strong means the same thing in all these expressions:
having the strength, physical power or conviction to do something/ not being easily defeated
So, to see the differences in meaning, we have to examine the verbs be, stay, keep, get, become, and remain.
BE STRONG
Be refers to a state: I am strong. You are strong. He is strong. This is our present state.
If someone is not strong, you can tell them:
- Don’t let them make you cry. Be strong.
STAY STRONG/ REMAIN STRONG
Stay and remain are synonyms, both verbs mean being in the same state/ not changing.
If someone is strong and you would like him or her to continue being strong, you can tell them:
- You’ve been doing so well so far. Just try to stay strong.
Stay strong is what people usually say to each other. Remain strong sounds more formal:
- Even though she received embarrassing questions, Charlize remained strong and answered all of them.
GET STRONG/ BECOME STRONG
Both get and become mean start to be. Here are some examples of how to use get strong and become strong:
- The illness left Sharon really weak. She needed to get stronger to be able to go back to work.
- If you want to get really strong, you should start coming to the gym with me.
- Christine has become such a strong woman since she left her husband.
- What should I do to become strong?
To learn when to use get and become, read Difference between GET and BECOME with examples!
KEEP STRONG
While the verb keep is often used to mean continue/ not to stop, normally it is not used together with adjectives. It’s used together with gerunds (verb+ing): keep smiling, keep working, keep learning. It is possible to say keep being strong, but it’s not a common expression.
