Tenses

The Simple Tenses
Simple Present	The watches TV every day.
Simple Past	It snowed yesterday.
Simple Future	It will snow tomorrow. It is going to snow tomorrow.
The Progressive Tenses
Present Progressive	Tom is sleeping right now.
Past Progressive	Tom was sleeping when I arrived.
Future Progressive	Tom will be sleeping when we arrive.
The Perfect Tenses
Present Perfect	Tome has already eaten.
Past Perfect	Tom had already eaten when his friend arrived.
Future Perfect	Tom will already have eaten when his friend arrives.
The Perfect Progressive Tenses
Present Perfect Progressive	Tom has been studying for two hours.
Past Perfect Progressive	Tom had been studying for two hours before his friend came.
Future Perfect Progressive	Tom will have been studying for two hours by the time his friend arrives. When Professor Jones retires next month, he will have tought or will have been teaching for 45 years.