---
title: Ascertain the cause of the northern and southern lights. — The night sky and outdoor myths · tree and pragmatics
description: Ascertain the cause of the northern and southern lights. Exam question 4 of lesson 240 «The night sky and outdoor myths» of the everyday course of Mova's primary school, with the dependency tree and pragmatics of the question and of each option; Mova's choice was wrong.
---

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# Exam question 4 · The night sky and outdoor myths

<!-- .ven lang=en -->
Ascertain the cause of the northern and southern lights.

<!-- .vintro -->
**Mova's choice:** option 1 · **The right answer:** option 2 · wrong ✗ · **Who acts:** you · **What happens:** ascertain, cause · **To what, where:** cause, northern lights

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This is exam question 4 of lesson 240 «The night sky and outdoor myths» of the everyday course of Mova's primary school, asked in stiff, formal language. 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/everyday/240-night-sky-and-outdoor-myths/#e4).

## The question {#question}

```conllu
# sent_id = question:everyday:240-night-sky-and-outdoor-myths:e4:1
# text = Ascertain the cause of the northern and southern lights.
1	Ascertain	ascertain	VERB	VB	Mood=Imp|VerbForm=Fin	0	root	_	_
2	the	the	DET	DT	Definite=Def|PronType=Art	3	det	_	_
3	cause	cause	NOUN	NN	Number=Sing	1	obj	_	_
4	of	of	ADP	IN	_	9	case	_	_
5	the	the	DET	DT	Definite=Def|PronType=Art	9	det	_	_
6	northern	northern	ADJ	JJ	Degree=Pos	9	amod	_	_
7	and	and	CCONJ	CC	_	8	cc	_	_
8	southern	southern	ADJ	JJ	Degree=Pos	6	conj	_	_
9	lights	light	NOUN	NNS	Number=Plur	3	nmod	_	SpaceAfter=No
10	.	.	PUNCT	.	_	1	punct	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **ascertain** | imperative | you *not said here* | the cause of the northern lights |  |  |  |  | vn discover-84 «NP V NP»: agent=Agent cause=Topic |
| 2 | **cause** |  |  | the northern lights |  |  |  |  | nom cause «event transitive»: of=patient |

<!-- .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 -->
Lightning storms high above the clouds

```conllu
# sent_id = question:everyday:240-night-sky-and-outdoor-myths:e4:o1:1
# text = Lightning storms high above the clouds
1	Lightning	lightning	NOUN	NN	Number=Sing	2	compound	_	_
2	storms	storm	NOUN	NNS	Number=Plur	3	nsubj	_	_
3	high	high	ADJ	JJ	Degree=Pos	0	root	_	_
4	above	above	ADP	IN	_	6	case	_	_
5	the	the	DET	DT	Definite=Def|PronType=Art	6	det	_	_
6	clouds	cloud	NOUN	NNS	Number=Plur	3	obl	_	_
```

<!-- .note -->
The frames reader finds no event or fact in this sentence.

### Option 2 · ✓ the right answer {#o2}

<!-- .ven lang=en -->
Particles from the Sun cause the air near the poles to glow

```conllu
# sent_id = question:everyday:240-night-sky-and-outdoor-myths:e4:o2:1
# text = Particles from the Sun cause the air near the poles to glow
1	Particles	particle	NOUN	NNS	Number=Plur	5	nsubj	_	_
2	from	from	ADP	IN	_	4	case	_	_
3	the	the	DET	DT	Definite=Def|PronType=Art	4	det	_	_
4	Sun	Sun	PROPN	NNP	Number=Sing	1	nmod	_	_
5	cause	cause	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	air	air	NOUN	NN	Number=Sing	5	obj	_	_
8	near	near	ADP	IN	_	10	case	_	_
9	the	the	DET	DT	Definite=Def|PronType=Art	10	det	_	_
10	poles	pole	NOUN	NNS	Number=Plur	5	obl	_	_
11	to	to	PART	TO	_	12	mark	_	_
12	glow	glow	VERB	VB	VerbForm=Inf	5	advcl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **cause** | present | Particles from the Sun | the air |  | the poles |  |  | vn engender-27.1-1 «NP V NP»: agent=Precondition air=Patient |
| 2 | **glow** | to-infinitive | Particles from the Sun *not said here* |  |  |  |  |  | vn light\_emission-43.1 «NP V»: agent=Theme |

### Option 3 {#o3}

<!-- .ven lang=en -->
Moonlight reflected from polar ice

```conllu
# sent_id = question:everyday:240-night-sky-and-outdoor-myths:e4:o3:1
# text = Moonlight reflected from polar ice
1	Moonlight	moonlight	NOUN	NN	Number=Sing	2	nsubj	_	_
2	reflected	reflect	VERB	VBD	Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin	0	root	_	_
3	from	from	ADP	IN	_	5	case	_	_
4	polar	polar	ADJ	JJ	Degree=Pos	5	amod	_	_
5	ice	ice	NOUN	NN	Number=Sing	2	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **reflect** | past | Moonlight |  |  | polar ice |  |  | vn focus-87.1-1 «NP V»: agent=Agent |

### Option 4 {#o4}

<!-- .ven lang=en -->
Fires burning in the far north

```conllu
# sent_id = question:everyday:240-night-sky-and-outdoor-myths:e4:o4:1
# text = Fires burning in the far north
1	Fires	fire	NOUN	NNS	Number=Plur	0	root	_	_
2	burning	burn	VERB	VBG	VerbForm=Ger	1	acl	_	_
3	in	in	ADP	IN	_	6	case	_	_
4	the	the	DET	DT	Definite=Def|PronType=Art	6	det	_	_
5	far	far	ADJ	JJ	Degree=Pos	6	amod	_	_
6	north	north	NOUN	NN	Number=Sing	2	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **burn** | gerund | Fires *not said here* |  |  | the far north |  |  | vn light\_emission-43.1 «NP V PP.location»: agent=Theme in north=Location |

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**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.

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- ← previous: [The night sky and outdoor myths, exam 3](https://md.mova.elamur.ai/free/en/corpora/questions/everyday/240-night-sky-and-outdoor-myths/e3/)
- next →: [Safe toys for you and little ones, test 1](https://md.mova.elamur.ai/free/en/corpora/questions/everyday/241-safe-toys/t1/)
- ↑ back to [The night sky and outdoor myths](https://md.mova.elamur.ai/free/en/corpora/questions/everyday/240-night-sky-and-outdoor-myths/)