---
title: Silver tarnishes because it reacts with sulphur gases in the air and… — Tarnish and how metals change · tree and pragmatics
description: Silver tarnishes because it reacts with sulphur gases in the air and makes a thin black layer. Who acts: Silver. A sentence of the lesson «Tarnish and how metals change» of the chemistry course of Mova's primary school with its dependency tree and the pragmatics of every clause.
---

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# Tarnish and how metals change, sentence 8

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Silver tarnishes because it reacts with sulphur gases in the air and makes a thin black layer.

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**Who acts:** Silver · **What happens:** tarnish, react, make · **To what, where:** thin black layer

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This is a sentence of the lesson «Tarnish and how metals change» of the chemistry 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 (Silver), what happens, when and where, as Mova's frames read it from the tree.

## The tree {#tree}

```conllu
# sent_id = school:chemistry:014-tarnish-and-how-metals-change.lesson:8
# text = Silver tarnishes because it reacts with sulphur gases in the air and makes a thin black layer.
# source = school lesson (ours)
# course = chemistry
# lesson = 014-tarnish-and-how-metals-change.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): no change
1	Silver	silver	NOUN	NN	Number=Sing	2	nsubj	_	_
2	tarnishes	tarnish	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
3	because	because	SCONJ	IN	_	5	mark	_	_
4	it	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	5	nsubj	_	_
5	reacts	react	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	2	advcl	_	_
6	with	with	ADP	IN	_	8	case	_	_
7	sulphur	sulphur	NOUN	NN	Number=Sing	8	compound	_	_
8	gases	gas	NOUN	NNS	Number=Plur	5	obl	_	_
9	in	in	ADP	IN	_	11	case	_	_
10	the	the	DET	DT	Definite=Def|PronType=Art	11	det	_	_
11	air	air	NOUN	NN	Number=Sing	8	nmod	_	_
12	and	and	CCONJ	CC	_	13	cc	_	_
13	makes	make	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	5	conj	_	_
14	a	a	DET	DT	Definite=Ind|PronType=Art	17	det	_	_
15	thin	thin	ADJ	JJ	Degree=Pos	17	amod	_	_
16	black	black	ADJ	JJ	Degree=Pos	17	amod	_	_
17	layer	layer	NOUN	NN	Number=Sing	13	obj	_	_
18	.	.	PUNCT	.	_	2	punct	_	_
```

## Pragmatics {#pragmatics}

<!-- .note -->
No stored speech act for this sentence.

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| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **tarnish** | present | Silver |  |  |  |  |  | vn entity\_specific\_cos-45.5 «NP.patient V»: agent=Patient |
| 2 | **react** | present | silver |  |  |  |  | with sulphur gases in the air | vn respond-113 «NP V PP.predicate»: agent=Agent with gas=Eventuality |
| 3 | **make** | present | silver *not said here* | a thin black layer |  |  |  |  | vn build-26.1-1 «NP.asset V NP»: agent=Asset layer=Product |

<!-- .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:chemistry:014-tarnish-and-how-metals-change.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): no change. **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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