---
title: A magnetised needle on a leaf floating in water turns to point north… — Compasses and the magnetic Earth · tree and pragmatics
description: A magnetised needle on a leaf floating in water turns to point north; sailors used compasses like this nearly a thousand years ago. Who acts: leaf, magnetised needle, sailors. A sentence of the lesson «Compasses and the magnetic Earth» of the physics course of Mova's primary school with its dependen
---

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# Compasses and the magnetic Earth, sentence 8

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A magnetised needle on a leaf floating in water turns to point north; sailors used compasses like this nearly a thousand years ago.

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**Who acts:** leaf, magnetised needle, sailors · **What happens:** magnetise, float, turn, point, use · **To what, where:** water, compasses

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This is a sentence of the lesson «Compasses and the magnetic Earth» of the physics course of Mova's primary school. The page gives its syntax tree — a dependency tree in the style of Universal Dependencies — and its pragmatics clause by clause: who acts (leaf, magnetised needle, sailors), what happens, when and where, as Mova's frames read it from the tree.

## The tree {#tree}

```conllu
# sent_id = school:physics:030-compasses-and-the-magnetic-earth.lesson:8
# text = A magnetised needle on a leaf floating in water turns to point north; sailors used compasses like this nearly a thousand years ago.
# source = school lesson (ours)
# course = physics
# lesson = 030-compasses-and-the-magnetic-earth.lesson
# annotation = Mova annot: Rust (en) → Haiku 5.5 (medium, Batches API) patches; gates UD 2.18; agreed by treeagree rules (Stanza, Trankit, spaCy trf): R5-strong ×2
1	A	a	DET	DT	Definite=Ind|PronType=Art	3	det	_	_
2	magnetised	magnetise	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	3	amod	_	_
3	needle	needle	NOUN	NN	Number=Sing	10	nsubj	_	_
4	on	on	ADP	IN	_	6	case	_	_
5	a	a	DET	DT	Definite=Ind|PronType=Art	6	det	_	_
6	leaf	leaf	NOUN	NN	Number=Sing	3	nmod	_	_
7	floating	float	VERB	VBG	VerbForm=Ger	6	acl	_	_
8	in	in	ADP	IN	_	9	case	_	_
9	water	water	NOUN	NN	Number=Sing	7	obl	_	_
10	turns	turn	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
11	to	to	PART	TO	_	12	mark	_	_
12	point	point	VERB	VB	VerbForm=Inf	7	xcomp	_	_
13	north	north	ADV	RB	_	12	advmod	_	_
14	;	;	PUNCT	,	_	10	punct	_	_
15	sailors	sailor	NOUN	NNS	Number=Plur	16	nsubj	_	_
16	used	use	VERB	VBD	Mood=Ind|Number=Plur|Person=3|Tense=Past|VerbForm=Fin	10	parataxis	_	_
17	compasses	compass	NOUN	NNS	Number=Plur	16	obj	_	_
18	like	like	ADP	IN	_	19	case	_	_
19	this	this	PRON	DT	Number=Sing|PronType=Dem	17	nmod	_	_
20	nearly	nearly	ADV	RB	_	22	advmod	_	_
21	a	a	DET	DT	Definite=Ind|PronType=Art	22	det	_	_
22	thousand	thousand	NUM	CD	NumForm=Word|NumType=Card	23	nummod	_	_
23	years	year	NOUN	NNS	Number=Plur	24	obl:unmarked	_	Agree=R5-strong|Haiku=16:obl:unmarked
24	ago	ago	ADV	RB	_	16	advmod	_	Agree=R5-strong|Haiku=23:advmod
25	.	.	PUNCT	.	_	10	punct	_	_
```

## Pragmatics {#pragmatics}

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- form: statement
- act: assert
- voice: narrator
- polarity: none
- teacher: kept the draft

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| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **magnetise** | participle |  |  |  |  |  |  | tree rules |
| 2 | **float** | gerund | a leaf *not said here* |  |  | water |  |  | tree rules |
| 3 | **turn** | present | a magnetised needle on a leaf |  |  |  |  |  | vn roll-51.3.1 «NP.theme V»: agent=Theme |
| 4 | **point** | to-infinitive | a leaf *not said here* |  |  |  |  | north *property* | vn wink-40.3.1 «NP V»: agent=Agent |
| 5 | **use** | past | sailors | compasses |  |  |  | like this; ago *property* | vn eat-39.1 «NP V NP»: agent=Agent compass=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.

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**Licence: [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/)**, as the whole of Mova corpus 0.4, of which this treebank (the agreed school, `mova-school-agreed-en.conllu`) is part. The lessons were written for Mova's primary school. Sentence `school:physics:030-compasses-and-the-magnetic-earth.lesson:8`.

**The tree:** Mova annot: Rust (en) → Haiku 5.5 (medium, Batches API) patches; gates UD 2.18; agreed by treeagree rules (Stanza, Trankit, spaCy trf): R5-strong ×2. **The frames** are read from the tree by Mova's frames reader (`prag`) when this page is built, the lesson read in order, so a pronoun may be resolved from an earlier sentence.

See the [release 0.4](https://md.mova.elamur.ai/free/en/releases/0.4/).

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