broken English; halting English
Refers to English spoken with poor grammar, limited vocabulary, or hesitant delivery, often by a non-native speaker.
He asked for directions in broken English.
Even broken English is enough if you can make yourself understood.
片言 means 'baby talk' or 'broken speech' in general; 片言英語 specifically refers to broken English.
Compound of 片言 (かたこと, 'broken speech') and 英語 (えいご, 'English').