Learning Goals 3 min
By the end of this lesson you will be able to:
- Drag the purple say [Hello!] block (no time) onto the Script Area.
- Change the speech bubble's text by typing inside the white text box.
- Clear a speech bubble by snapping an empty say [ ] after a short wait.
Warm-Up 7 min
You've built a cat that moves, turns, and dances. Now starts a brand-new arc: Cat's Talking Cartoon. Over seven lessons you'll give the cat a voice, a thought bubble, new costumes, and the ability to grow and vanish — all leading to a tiny cartoon you can share. Today is Lesson 1 of that arc: you teach the cat to speak.
Quick-fire puzzle
Aisyah snapped these three blocks together. She clicked the green flag. What appears on the Stage — and for how long?
when flag clicked
say [Hi!]
move (50) steps
Reveal the answer
A speech bubble pops up over the cat saying "Hi!", then the cat slides 50 steps to the right. The bubble stays on the screen — forever — even after the script finishes. This is the sticky say block. It puts a bubble up and walks away.
To clear it, you would need another say [ ] block with an empty text box. We'll meet that trick today.
New Concept — the sticky speech bubble 15 min
A speech bubble is the little white cloud with a pointy tail that appears above your sprite. It's how the cat talks to your audience. Today's block is say [Hello!] — the sticky version, with no time.
Blocks reference
| Block | Category | What it does |
|---|---|---|
| say [Hello!] | Looks (purple) | Puts a speech bubble above the sprite with the text "Hello!". The bubble stays until something clears it. |
| say [ ] | Looks (purple) | The same block — but with nothing in the text box. This clears any speech bubble. |
One block. Two jobs.
It's the same purple block in both rows above — the only difference is what you type inside the white text box. Type a message: a bubble appears. Leave it empty: any existing bubble vanishes.
when flag clicked
say [Selamat datang!]
Sticky vs timed — a quick preview
There are two say blocks in the Looks category. They look almost identical:
- say [Hello!] — sticky. The bubble stays up until another block clears it. This is today.
- say [Hello!] for (2) seconds — timed. The bubble fades after the seconds run out. Next lesson.
Why it matters
The sticky say is perfect when you want a label that hangs around — a name tag, a title screen, a hint that should stay visible until the player moves on. The timed say is perfect for short lines of dialogue. Two flavours, two jobs.
Worked Example — Aisyah's Cat says hello, then goes quiet 15 min
We'll build a tiny greeting. Click the green flag → cat says "Selamat datang!" → 2 seconds later, the bubble disappears.
Step 1 — Set up
Open Scratch. Make sure your cat is at the centre (x = 0, y = 0). Click on the cat in the Sprite list so it's selected.
Step 2 — Drag the hat block
From the yellow Events category, drag when ⚑ clicked into the Script Area.
Step 3 — Find the purple Looks category
In the Blocks Panel on the left, click the purple eye icon — that's Looks. The panel turns purple.
Step 4 — Drag the sticky say block
Find say [Hello!] — the one with only one input box, no seconds. Snap it under the yellow hat. Click on the word "Hello!" and replace it with Selamat datang!
when flag clicked
say [Selamat datang!]
Step 5 — Add a wait
From the orange Control category, drag wait (1) seconds. Change 1 to 2. Snap it under the say block.
Step 6 — Add the empty say to clear the bubble
Go back to the purple Looks category. Drag another say [Hello!] block (the sticky one again). Click the text box and delete everything inside so it's completely empty. Snap it under the wait.
Step 7 — Run it
Click the green flag. The cat says "Selamat datang!". After 2 seconds, the bubble pops. Silence on the Stage.
What changed: compared to using only one say block (the bubble would stay forever), the empty say at the end clears it. This is the "sticky-then-clear" pattern.
The full assembled stack
when flag clicked
say [Selamat datang!]
wait (2) seconds
say []
Try It Yourself — three small builds 12 min
Goal: Make the cat introduce itself. Change the say text to your own name (or your sprite's name).
when flag clicked
say [I am Aisyah's Cat!]
Think: No wait, no empty say — so the bubble stays up forever. Click the flag again, again, again. The text doesn't change, because the cat is just re-running the same say block.
Goal: Make the cat change its mind. The bubble should swap from one sentence to another after 3 seconds.
when flag clicked
say [I love kuih.]
wait (3) seconds
say [Actually, roti canai.]
Think: Two say blocks in a row — the second one replaces the first. Sticky bubbles don't pile up; each new say overwrites the last. Bubble math: at most one bubble per sprite, ever.
Goal: Move and talk at the same time. Make the cat walk while a label sits over it like a name tag.
when flag clicked
say [Aisyah's Cat]
move (100) steps
wait (2) seconds
move (100) steps
say []
Think: The bubble travels with the cat — it's stuck to the sprite, not to the Stage. The empty say at the end is the cleanup. Without it, the name tag would hang in the air forever.
Mini-Challenge — Greeting then a dance 5 min
"The polite cat"
Build a script that greets the audience, holds the greeting on screen for 2 seconds, clears it, then spins 360 degrees (24 turns of 15 degrees each — use a repeat (24) from your earlier lessons).
It works if:
- Clicking the green flag pops a "Hello!" bubble over the cat.
- After 2 seconds the bubble disappears (not fades — vanishes because you cleared it).
- The cat then spins one full circle and ends up facing right (Direction = 90) again.
- You used today's sticky say [Hello!] and an empty say [ ], plus repeat + turn from earlier lessons.
Reveal one valid solution
when flag clicked
say [Hello!]
wait (2) seconds
say []
repeat (24)
turn cw (15) degrees
end
The clear (empty say) happens before the spin starts, so the cat dances without a label. 24 × 15° = 360° = one full circle.
Recap 2 min
Today you met the purple Looks blocks and the sticky say [Hello!]. It puts a speech bubble over your sprite that stays until you clear it. Clear it with the same block, but leave the text box empty. Next lesson: the timed version, which clears itself.
- Looks (category)
- The purple block category. Holds all the blocks that change how a sprite looks — including speech bubbles, costumes, and size.
- Speech bubble
- The little white cloud with a tail that appears over a sprite when a say block runs.
- say [Hello!] (block)
- Sticky version. Puts a bubble up and walks away. The bubble stays until another say block changes or clears it.
- Sticky vs timed
- "Sticky" means the bubble stays forever. "Timed" (next lesson) means it fades after N seconds.
Homework 1 min
The three-line greeting. Make your cat say three short Malay greetings in a row, with a 2-second pause between each. End with an empty bubble so the Stage goes quiet.
- Open Scratch. Drag a green-flag hat.
- Snap a sticky say with "Selamat pagi!", then a 2-second wait, then a say with "Apa khabar?", then a 2-second wait, then a say with "Jumpa lagi!", then a 2-second wait, then an empty say.
- Click the green flag and watch the three messages cycle through.
- Take a screenshot of your Script Area showing all the blocks.
Bring back next class:
- Your screenshot.
- Your written answer: "What happens if you remove the final empty say block? Why?"
Heads up for next class: SCR-L01-24 introduces the timed say block — say [Hello!] for (2) seconds — which clears itself automatically. You'll learn when to use sticky and when to use timed.