老(是)
lǎo ( shì )
Using "always" as a complaint with "laoshi"
老是 also means "always", but only ever as a grumble.
Subj. + 老(是) + Verb
How it works
你怎么老是加班? — why are you always working late? The speaker is not pleased.
总是 is neutral; 老是 is a complaint. Swapping them changes the tone entirely.
The 是 can be dropped: 他老迟到.
Examples
nǐ zěn me lǎo shì jiā bān?
你怎么老是加班？
Why are you always working overtime?
tā lǎo shì wàng jì guān dēng
他老是忘记关灯。
He's forever forgetting to turn the light off.
bié lǎo kàn shǒu jī
别老看手机。
Stop staring at your phone all the time.