stammer

To speak with pauses and repeated sounds, finding it hard to get words out.

stammer in a sentence

'I-I didn't mean to break it,' Sam stammered, staring at the floor.
Priya sometimes stammers on words that start with 'p', but that did not stop her reading her whole poem to the school.

stutter, hesitate

summarise: To give the main points of something in a short way.
summon: To officially call someone to come to you.
taunt: To tease someone in a cruel way to upset them.
terse: Using very few words, often in an unfriendly way.
tumult: A loud, confused noise made by an excited crowd.
unison: Doing or saying something all together at exactly the same time.
uproar: A storm of loud noise and angry shouting from lots of people.
vouch: To say from your own knowledge that something is true or someone is good.

Plain-English guides to each test, from the councils’ own pages: Kent Test · Medway Test · Bucks Secondary Transfer Test