“Keep up” is often used to refer to maintaining or continuing something.
1. “Keep up (with something)” – (intransitive) To stay informed or be able to understand something that is happening or changing very fast.
- “I try to keep up with the news regarding the pandemic.”
- “It’s difficult to keep up with all the advancements in technology.”
2. “Keep up (with someone/something) – (intransitive) To stay level or equal with someone or something.
- “You have to stay motivated if you want to keep up.”
- “I can’t keep up with Ben when we go hiking.”
This is often used in business English.
- “It’s important to keep up with trends and technological advancements to remain competitive.”
3. “Keep up (with something)” – (separable) To continue to do something.
- “Keep up the good work.”
- “If you keep up with the payments, you won’t get charged interest on your credit card.”
* Please note: “Keep up the good work” is a common expression of encouragement.
If you want to use pronouns, then you separate the phrasal verb.
Not – “Keep up it.”
4. “Keep (someone) up” – (separated) “To prevent someone from sleeping.
- “The neighbour’s loud music kept us up until two in the morning.”
- “Drinking coffee at this hour will keep you up tonight.”
“Keep up appearances”
– To pretend to be something than what you really are because you do not want people to know how bad your situation is.
- “They had an unhappy marriage but kept up appearances for the sake of their children.”
- “She tried to appear cheerful but couldn’t keep it up anymore.”
Original post: 3 September 2020