Creates sentence parts based on split sentences.

@param {Array}   sentences   The array with split sentences.
@param {string}  language    The language for which to create sentence parts.

@returns {Array} The array with sentence parts.
function createSentenceParts( sentences, language ) {
	const auxiliaryRegex = languageVariables[ language ].auxiliaryRegex;
	const SentencePart = languageVariables[ language ].SentencePart;
	const sentenceParts = [];
	forEach( sentences, function( part ) {
		const foundAuxiliaries = sanitizeMatches( part.match( auxiliaryRegex || [] ) );
		sentenceParts.push( new SentencePart( part, foundAuxiliaries, languageVariables[ language ].locale ) );
	} );
	return sentenceParts;
}