/**
 * This function adds pluralization support to every String object.
 * @param str The subject string.
 * @param plural Overrides normal output with said String.(optional)
 * @returns Singular English language nouns are returned in plural form.
 * @example
 *
 *     const inflection = require( 'inflection' );
 *
 *     inflection.pluralize( 'person' ); // === 'people'
 *     inflection.pluralize( 'octopus' ); // === 'octopuses'
 *     inflection.pluralize( 'Hat' ); // === 'Hats'
 *     inflection.pluralize( 'person', 'guys' ); // === 'guys'
 */
export declare function pluralize(str: string, plural?: string): string;
/**
 * This function adds singularization support to every String object.
 * @param str The subject string.
 * @param singular Overrides normal output with said String.(optional)
 * @returns Plural English language nouns are returned in singular form.
 * @example
 *
 *     const inflection = require( 'inflection' );
 *
 *     inflection.singularize( 'people' ); // === 'person'
 *     inflection.singularize( 'octopuses' ); // === 'octopus'
 *     inflection.singularize( 'Hats' ); // === 'Hat'
 *     inflection.singularize( 'guys', 'person' ); // === 'person'
 */
export declare function singularize(str: string, singular?: string): string;
/**
 * This function will pluralize or singularlize a String appropriately based on a number value
 * @param str The subject string.
 * @param count The number to base pluralization off of.
 * @param singular Overrides normal output with said String.(optional)
 * @param plural Overrides normal output with said String.(optional)
 * @returns English language nouns are returned in the plural or singular form based on the count.
 * @example
 *
 *     const inflection = require( 'inflection' );
 *
 *     inflection.inflect( 'people' 1 ); // === 'person'
 *     inflection.inflect( 'octopuses' 1 ); // === 'octopus'
 *     inflection.inflect( 'Hats' 1 ); // === 'Hat'
 *     inflection.inflect( 'guys', 1 , 'person' ); // === 'person'
 *     inflection.inflect( 'inches', 1.5 ); // === 'inches'
 *     inflection.inflect( 'person', 2 ); // === 'people'
 *     inflection.inflect( 'octopus', 2 ); // === 'octopuses'
 *     inflection.inflect( 'Hat', 2 ); // === 'Hats'
 *     inflection.inflect( 'person', 2, null, 'guys' ); // === 'guys'
 */
export declare function inflect(
    str: string,
    count: number,
    singular?: string,
    plural?: string,
): string;