check up on
InseparableThe verb and particle never split. The object always follows the whole phrase.
How to say it
Main stress lands on the first particle: check UP on. The trailing “on” reduces almost to nothing — expect a schwa, not a full vowel.
Link across the gap. The final /k/ of “check” moves onto the particle and starts its syllable: “check up” is said “che-ckup”. Pausing between the words is what makes phrasal verbs sound recited rather than spoken.
Verb vs noun
As a noun the stress flips to the front: the verb is check UP, the noun is CHECKUP. Same two words, different beat — “to check UP” is the action, “a checkup” is the thing. Getting this backwards makes the sentence land oddly even when every sound is right.
What it means
To verify that someone is doing what they should be, or that they are well.
- “The doctor checked up on the patient after surgery.”
- “Her parents call every evening to check up on her.”
Similar: monitor, look in on