Verbs: Lay/Lie

EXPLANATION/EXPLICAÇÃO:

These verbs, are often confused when 'Lie' is used in the sense of being horizontal. This is an understandable mistake given their similar meaning and the fact that the Past Tense of the verb 'Lie' is 'Lay'.

To Lay - Laid - Laid
To Lie - Lay - Lain

If we focus on the Present tense, we can discern the difference between them quite easily:

Lay: put something or someone down/horizontally.

Being a transitive verb, Lay requires a direct object. You can't just lay, you have to lay something or someone.

Examples:

Present Tense: He lays the book on the table.
Past Tense: He laid his head to rest.
Past Perfect Tense: She had laid the clothes on the bed.

Lie: to be in a horizontal position.

Lie is an intransitive verb, therefore, doesn't have a direct object.

Examples:

Present Tense: I lie awake.
Past Tense: The clothes lay on the bed.
Past Perfect Tense: She had lain in hospital bed for three weeks.

Source: Oxford Dictionaries