---
title: Ascertain the principal reason for which a crocodile is observed to… — Crocodiles and alligators · tree and pragmatics
description: Ascertain the principal reason for which a crocodile is observed to rotate repeatedly in the water while grasping its prey. Exam question 3 of lesson 29 «Crocodiles and alligators» of the biology course of Mova's primary school, with the dependency tree and pragmatics of the question and of each opt
---

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# Exam question 3 · Crocodiles and alligators

<!-- .ven lang=en -->
Ascertain the principal reason for which a crocodile is observed to rotate repeatedly in the water while grasping its prey.

<!-- .vintro -->
**Mova's choice:** option 1 · **The right answer:** option 1 · right ✓ · **Who acts:** you · **What happens:** ascertain, observe, rotate, grasp · **To what, where:** principal reason, crocodile, water, prey

<!-- .vabout -->
This is exam question 3 of lesson 29 «Crocodiles and alligators» of the biology 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/biology/29-crocodiles-and-alligators/#e3).

## The question {#question}

```conllu
# sent_id = question:biology:29-crocodiles-and-alligators:e3:1
# text = Ascertain the principal reason for which a crocodile is observed to rotate repeatedly in the water while grasping its prey.
1	Ascertain	ascertain	VERB	VB	Mood=Imp|VerbForm=Fin	0	root	_	_
2	the	the	DET	DT	Definite=Def|PronType=Art	4	det	_	_
3	principal	principal	ADJ	JJ	Degree=Pos	4	amod	_	_
4	reason	reason	NOUN	NN	Number=Sing	1	obj	_	_
5	for	for	ADP	IN	_	6	case	_	_
6	which	which	PRON	WDT	PronType=Rel	10	obl	_	_
7	a	a	DET	DT	Definite=Ind|PronType=Art	8	det	_	_
8	crocodile	crocodile	NOUN	NN	Number=Sing	10	nsubj:pass	_	_
9	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	10	aux:pass	_	_
10	observed	observe	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	4	acl:relcl	_	_
11	to	to	ADP	IN	_	12	case	_	_
12	rotate	rotate	VERB	VB	VerbForm=Inf	10	xcomp	_	_
13	repeatedly	repeatedly	ADV	RB	_	10	advmod	_	_
14	in	in	ADP	IN	_	16	case	_	_
15	the	the	DET	DT	Definite=Def|PronType=Art	16	det	_	_
16	water	water	NOUN	NN	Number=Sing	10	obl	_	_
17	while	while	SCONJ	IN	_	18	mark	_	_
18	grasping	grasp	VERB	VBG	Tense=Pres|VerbForm=Part	10	advcl	_	_
19	its	its	PRON	PRP$	Case=Gen|Gender=Neut|Number=Sing|Person=3|Poss=Yes|PronType=Prs	20	nmod:poss	_	_
20	prey	prey	NOUN	NN	Number=Sing	18	obj	_	SpaceAfter=No
21	.	.	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 principal reason |  |  |  |  | vn discover-84 «NP V NP»: agent=Agent reason=Topic |
| 2 | **observe** | present · passive |  | a crocodile |  | the water |  | for the principal reason; repeatedly *property* | tree rules |
| 3 | **rotate** | infinitive |  |  |  |  |  |  | vn modes\_of\_being\_with\_motion-47.3 «NP V»: agent=Theme |
| 4 | **grasp** | gerund |  | crocodile's prey |  |  |  |  | vn comprehend-87.2-1 «NP V NP»: agent=Experiencer prey=Stimulus |

<!-- .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 · ✓ the right answer {#o1}

<!-- .ven lang=en -->
It is incapable of chewing and so tears off portions

```conllu
# sent_id = question:biology:29-crocodiles-and-alligators:e3:o1:1
# text = It is incapable of chewing and so tears off portions
1	It	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	3	nsubj	_	_
2	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	3	cop	_	_
3	incapable	incapable	ADJ	JJ	Degree=Pos	0	root	_	_
4	of	of	SCONJ	IN	_	5	mark	_	_
5	chewing	chew	VERB	VBG	Tense=Pres|VerbForm=Part	3	advcl	_	_
6	and	and	CCONJ	CC	_	8	cc	_	_
7	so	so	ADV	RB	_	8	advmod	_	_
8	tears	tear	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	3	conj	_	_
9	off	off	ADP	RP	_	8	compound:prt	_	_
10	portions	portion	NOUN	NNS	Number=Plur	8	obj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **is** | present | It |  |  |  |  | incapable *property* | tree rules |
| 2 | **chew** | gerund |  |  |  |  |  |  | vn chew-39.2 «NP V»: agent=Agent |
| 3 | **tear off** | present |  | portions |  |  |  |  | vn run-51.3.2 «PP.location V NP»: agent=Initial\_Location portion=Theme |

### Option 2 {#o2}

<!-- .ven lang=en -->
It is signalling to the other crocodiles that the prey is its own

```conllu
# sent_id = question:biology:29-crocodiles-and-alligators:e3:o2:1
# text = It is signalling to the other crocodiles that the prey is its own
1	It	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	3	nsubj	_	_
2	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	3	aux	_	_
3	signalling	signall	VERB	VBG	Tense=Pres|VerbForm=Part	0	root	_	_
4	to	to	ADP	IN	_	7	case	_	_
5	the	the	DET	DT	Definite=Def|PronType=Art	7	det	_	_
6	other	other	ADJ	JJ	Degree=Pos	7	amod	_	_
7	crocodiles	crocodile	NOUN	NNS	Number=Plur	3	obl	_	_
8	that	that	PRON	WDT	PronType=Rel	13	nsubj	_	_
9	the	the	DET	DT	Definite=Def|PronType=Art	10	det	_	_
10	prey	prey	NOUN	NN	Number=Sing	13	nsubj	_	_
11	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	13	cop	_	_
12	its	its	PRON	PRP$	Case=Gen|Gender=Neut|Number=Sing|Person=3|Poss=Yes|PronType=Prs	13	nmod:poss	_	_
13	own	own	ADJ	JJ	Degree=Pos	7	acl:relcl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **signall** | present · progressive | It |  |  |  |  | to the other crocodiles | tree rules |
| 2 | **is** | present | the other crocodiles |  |  |  |  | own *property* | tree rules |

### Option 3 {#o3}

<!-- .ven lang=en -->
It seeks to render itself dizzy

```conllu
# sent_id = question:biology:29-crocodiles-and-alligators:e3:o3:1
# text = It seeks to render itself dizzy
1	It	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	2	nsubj	_	_
2	seeks	seek	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
3	to	to	PART	TO	_	4	mark	_	_
4	render	render	VERB	VB	VerbForm=Inf	2	xcomp	_	_
5	itself	itself	PRON	PRP	Case=Acc|Gender=Neut|Number=Sing|Person=3|PronType=Prs|Reflex=Yes	4	obj	_	_
6	dizzy	dizzy	ADJ	JJ	Degree=Pos	4	xcomp	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **seek** | present | It |  |  |  |  |  | tree rules |
| 2 | **render** *not said to happen* | to-infinitive |  | itself *= it* |  |  |  | dizzy *property* | vn give-13.1 «NP V NP»: agent=Agent itself=Theme |

### Option 4 {#o4}

<!-- .ven lang=en -->
It is cleansing its prey

```conllu
# sent_id = question:biology:29-crocodiles-and-alligators:e3:o4:1
# text = It is cleansing its prey
1	It	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	3	nsubj	_	_
2	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	3	aux	_	_
3	cleansing	cleanse	VERB	VBG	Tense=Pres|VerbForm=Part	0	root	_	_
4	its	its	PRON	PRP$	Case=Gen|Gender=Neut|Number=Sing|Person=3|Poss=Yes|PronType=Prs	5	nmod:poss	_	_
5	prey	prey	NOUN	NN	Number=Sing	3	obj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **cleanse** | present · progressive | It | its prey |  |  |  |  | vn groom-41.1.2 «NP V NP»: agent=Agent prey=Patient |

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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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