---
title: Oil and water on a surface reduce friction, which is why wet floors… — Forces — pushes, pulls, friction and magnets · tree and pragmatics
description: Oil and water on a surface reduce friction, which is why wet floors are slippery. Who acts: Oil, friction. A sentence of the lesson «Forces — pushes, pulls, friction and magnets» of the world course of Mova's primary school with its dependency tree and the pragmatics of every clause.
---

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# Forces — pushes, pulls, friction and magnets, sentence 14

<!-- .ven lang=en -->
Oil and water on a surface reduce friction, which is why wet floors are slippery.

<!-- .vintro -->
**Who acts:** Oil, friction · **What happens:** reduce, be · **To what, where:** friction

<!-- .vabout -->
This is a sentence of the lesson «Forces — pushes, pulls, friction and magnets» of the world 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 (Oil, friction), what happens, when and where, as Mova's frames read it from the tree.

## The tree {#tree}

```conllu
# sent_id = school:world:051-forces.lesson:14
# text = Oil and water on a surface reduce friction, which is why wet floors are slippery.
# source = school lesson (ours)
# course = world
# lesson = 051-forces.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 ×1, R8-pos-agree ×1
1	Oil	oil	NOUN	NN	Number=Sing	7	nsubj	_	_
2	and	and	CCONJ	CC	_	3	cc	_	_
3	water	water	NOUN	NN	Number=Sing	1	conj	_	_
4	on	on	ADP	IN	_	6	case	_	_
5	a	a	DET	DT	Definite=Ind|PronType=Art	6	det	_	_
6	surface	surface	NOUN	NN	Number=Sing	1	nmod	_	Agree=R5-strong|Haiku=7:obl
7	reduce	reduce	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	Agree=R8-pos-agree|Haiku=0:root|HaikuPos=VERB:VB:VerbForm=Inf
8	friction	friction	NOUN	NN	Number=Sing	7	obj	_	_
9	,	,	PUNCT	,	_	16	punct	_	_
10	which	which	PRON	WDT	PronType=Rel	16	nsubj	_	_
11	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	16	cop	_	_
12	why	why	ADV	WRB	PronType=Int	16	advmod	_	_
13	wet	wet	ADJ	JJ	Degree=Pos	14	amod	_	_
14	floors	floor	NOUN	NNS	Number=Plur	16	nsubj	_	_
15	are	be	AUX	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	16	cop	_	_
16	slippery	slippery	ADJ	JJ	Degree=Pos	8	acl:relcl	_	_
17	.	.	PUNCT	.	_	7	punct	_	_
```

## Pragmatics {#pragmatics}

<!-- sa -->
- form: statement
- act: assert
- voice: narrator
- polarity: none
- teacher: kept the draft

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **reduce** | present | Oil on a surface and water | friction |  |  |  |  | vn limit-76 «NP V NP»: agent=Causer friction=Patient |
| 2 | **is** | present | friction |  |  |  |  | slippery *property* | tree rules |

<!-- .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:world:051-forces.lesson:14`.

**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 ×1, R8-pos-agree ×1. **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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- ← previous: [Forces — pushes, pulls, friction and m…, 13](https://md.mova.elamur.ai/free/en/corpora/school/world/51-forces/13/)
- next →: [Forces — pushes, pulls, friction and m…, 15](https://md.mova.elamur.ai/free/en/corpora/school/world/51-forces/15/)
- ↑ back to [the lesson](https://md.mova.elamur.ai/free/en/corpora/school/world/51-forces/)