Retrieve the language
A gerund is an -ing form used as a noun. As subject: Learning another language takes time (singular verb). As object: We enjoy meeting visitors. After a preposition: She is interested in joining. Avoid a bare verb where a gerund is required. A gerund can take an object: Organising a welcome event needs teamwork.
A present-participle clause usually has an active meaning: Burning fuel, the engine releases gases. A past-participle clause often has a passive meaning: Heated by sunlight, the surface warms. The understood subject must match the main-clause subject; avoid dangling participles. These shortened clauses may express reason, time or a related action, so expand them to check meaning.