---
title: Why does a pond freeze first at the top and not at the bottom? — Clever reasoning about water and matter · tree and pragmatics
description: Why does a pond freeze first at the top and not at the bottom? Test 6 · ★★★ of lesson 20 «Clever reasoning about water and matter» of the world course of Mova's primary school, with the dependency tree and pragmatics of the question and of each option; Mova's choice was wrong.
---

<!-- md -->
[Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/questions/world/20-reasoning-water-and-matter/t6/)

<!-- crumbs -->
[home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [questions](https://md.mova.elamur.ai/free/en/corpora/questions/) / [World](https://md.mova.elamur.ai/free/en/corpora/questions/world/) / [Clever reasoning about water and matter](https://md.mova.elamur.ai/free/en/corpora/questions/world/20-reasoning-water-and-matter/) / t6

# Test 6 · ★★★ · Clever reasoning about water and matter

<!-- .ven lang=en -->
Why does a pond freeze first at the top and not at the bottom?

<!-- .vintro -->
**Mova's choice:** option 1 · **The right answer:** option 4 · wrong ✗ · **What happens:** do · **To what, where:** pond freeze, top

<!-- .vabout -->
This is test 6 · ★★★ of lesson 20 «Clever reasoning about water and matter» of the world course of Mova's primary school. The page gives the question's syntax tree — a dependency tree in the style of Universal Dependencies — and its pragmatics clause by clause, then the 4 options as the student saw them, each with its tree and pragmatics. Every text is parsed by Mova itself. How the student answered it, with the score of every option and why: [the test at school](https://md.mova.elamur.ai/free/en/school-run/world/20-reasoning-water-and-matter/#t6).

## The question {#question}

```conllu
# sent_id = question:world:20-reasoning-water-and-matter:t6:1
# text = Why does a pond freeze first at the top and not at the bottom?
1	Why	why	ADV	WRB	PronType=Int	2	advmod	_	_
2	does	do	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
3	a	a	DET	DT	Definite=Ind|PronType=Art	5	det	_	_
4	pond	pond	NOUN	NN	Number=Sing	5	compound	_	_
5	freeze	freeze	NOUN	NN	Number=Sing	2	obj	_	_
6	first	first	ADV	RB	NumForm=Word|NumType=Ord	2	advmod	_	_
7	at	at	ADP	IN	_	9	case	_	_
8	the	the	DET	DT	Definite=Def|PronType=Art	9	det	_	_
9	top	top	NOUN	NN	Number=Sing	2	obl	_	_
10	and	and	CCONJ	CC	_	14	cc	_	_
11	not	not	PART	RB	Polarity=Neg	14	advmod	_	_
12	at	at	ADP	IN	_	14	case	_	_
13	the	the	DET	DT	Definite=Def|PronType=Art	14	det	_	_
14	bottom	bottom	NOUN	NN	Number=Sing	9	conj	_	SpaceAfter=No
15	?	?	PUNCT	.	_	2	punct	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **do** | present |  | a pond freeze |  | the top and the bottom |  | first *property* | vn act-114-1 «NP V NP»: agent=Agent freeze=Eventuality |

<!-- .note -->
One row per clause the reader finds. «not said here»: a role filled from the clause above. «roles by»: a VerbNet class and frame when one fits the verb, else the reader's rules on the tree.

## The options {#options}

### Option 1 · ← Mova's choice {#o1}

<!-- .ven lang=en -->
Ice sinks and piles up from the bottom

```conllu
# sent_id = question:world:20-reasoning-water-and-matter:t6:o1:1
# text = Ice sinks and piles up from the bottom
1	Ice	ice	NOUN	NN	Number=Sing	2	nsubj	_	_
2	sinks	sink	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
3	and	and	CCONJ	CC	_	4	cc	_	_
4	piles	pile	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	2	conj	_	_
5	up	up	ADP	RP	_	4	compound:prt	_	_
6	from	from	ADP	IN	_	8	case	_	_
7	the	the	DET	DT	Definite=Def|PronType=Art	8	det	_	_
8	bottom	bottom	NOUN	NN	Number=Sing	4	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **sink** | present | Ice |  |  |  |  |  | vn other\_cos-45.4 «NP.patient V»: agent=Patient |
| 2 | **pile up** | present | Ice *not said here* |  |  | the bottom |  |  | vn spray-9.7-1-1 «NP V PP.destination»: agent=Theme |

### Option 2 {#o2}

<!-- .ven lang=en -->
Frogs on the bottom melt the ice there

```conllu
# sent_id = question:world:20-reasoning-water-and-matter:t6:o2:1
# text = Frogs on the bottom melt the ice there
1	Frogs	frog	NOUN	NNS	Number=Plur	5	nsubj	_	_
2	on	on	ADP	IN	_	4	case	_	_
3	the	the	DET	DT	Definite=Def|PronType=Art	4	det	_	_
4	bottom	bottom	NOUN	NN	Number=Sing	1	nmod	_	_
5	melt	melt	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
6	the	the	DET	DT	Definite=Def|PronType=Art	7	det	_	_
7	ice	ice	NOUN	NN	Number=Sing	5	obj	_	_
8	there	there	ADV	RB	PronType=Dem	5	advmod	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **melt** | present | Frogs on the bottom | the ice |  | there |  |  | vn other\_cos-45.4-1 «NP V NP ADJ»: agent=Patient ice=Result |

### Option 3 {#o3}

<!-- .ven lang=en -->
The Sun warms only the top of the pond

```conllu
# sent_id = question:world:20-reasoning-water-and-matter:t6:o3:1
# text = The Sun warms only the top of the pond
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	Sun	Sun	PROPN	NNP	Number=Sing	3	nsubj	_	_
3	warms	warm	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	only	only	ADV	RB	_	6	advmod	_	_
5	the	the	DET	DT	Definite=Def|PronType=Art	6	det	_	_
6	top	top	NOUN	NN	Number=Sing	3	obj	_	_
7	of	of	ADP	IN	_	9	case	_	_
8	the	the	DET	DT	Definite=Def|PronType=Art	9	det	_	_
9	pond	pond	NOUN	NN	Number=Sing	6	nmod	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **warm** | present | the Sun | the top of the pond |  |  |  |  | vn other\_cos-45.4 «NP V NP.patient»: agent=Agent top=Patient |

### Option 4 · ✓ the right answer {#o4}

<!-- .ven lang=en -->
The surface touches the cold air, and ice floats

```conllu
# sent_id = question:world:20-reasoning-water-and-matter:t6:o4:1
# text = The surface touches the cold air, and ice floats
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	surface	surface	NOUN	NN	Number=Sing	3	nsubj	_	_
3	touches	touch	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	the	the	DET	DT	Definite=Def|PronType=Art	6	det	_	_
5	cold	cold	ADJ	JJ	Degree=Pos	6	amod	_	_
6	air	air	NOUN	NN	Number=Sing	3	obj	_	SpaceAfter=No
7	,	,	PUNCT	,	_	10	punct	_	_
8	and	and	CCONJ	CC	_	10	cc	_	_
9	ice	ice	NOUN	NN	Number=Sing	10	compound	_	_
10	floats	float	NOUN	NNS	Number=Plur	3	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **touch** | present | the surface | the cold air |  |  |  | ice floats *obl* | vn contiguous\_location-47.8-1 «NP V NP»: agent=Theme air=Co-Theme |

<!-- div src -->

**Text:** the tests of Mova's primary school, written for Mova (`world/data/school/`), as the course runner gave them to the student. **Trees:** Mova's own parse — the `en` model on the CPU, when the site is built — not checked by a teacher; they may be wrong. **Frames:** Mova's frames reader (`prag`), each text read on its own. Elamur Cosmic License.

<!-- /div -->

<!-- pn -->
- ← previous: [Clever reasoning about water and matter, test 5](https://md.mova.elamur.ai/free/en/corpora/questions/world/20-reasoning-water-and-matter/t5/)
- next →: [Clever reasoning about water and matter, test 7](https://md.mova.elamur.ai/free/en/corpora/questions/world/20-reasoning-water-and-matter/t7/)
- ↑ back to [Clever reasoning about water and matter](https://md.mova.elamur.ai/free/en/corpora/questions/world/20-reasoning-water-and-matter/)