underpin – Early Modern English verb conjugation

Notes:

• Compound forms (perfect, pluperfect) are formed either with 'have' or 'be'.
• Future is formed as in modern English, with auxiliary 'will'.
• Conditional is formed as in modern English, with auxiliary 'would'.
• Continuous forms are formed with auxiliary 'be' and gerund. Sometimes the gerund is preceded by 'a-'
• Plural forms in present lost the '-en' ending, and was used only as a stylistic affectation to indicate rural or old-fashioned speech.