Learn Swedish: Mitt lilla barn sover. - My little child is sleeping.

The noun barn (child) is an ett-word (ett barn). The word for "my" has to agree with the noun, so it becomes mitt. If you were talking about an en-word, like a dog (en hund), you would say min lilla hund.

Why is the adjective lilla used instead of litet if barn is an ett-word?

After a possessive pronoun like mitt (my), adjectives must take their definite form, which almost always ends in -a. So, even though barn is an ett-word, we use lilla instead of the indefinite neuter form litet.

If the adjective lilla is in the definite form, why isn't the noun definite too (barnet)?

This is a classic Swedish grammar rule! When you use a possessive word (like mitt, din, vår), the noun that follows must be in the indefinite form. The pattern is: possessive + definite adjective + indefinite noun (mitt lilla barn).

How do I know if sover means "sleeps" or "is sleeping"?

Swedish doesn't have a separate continuous tense (the "-ing" form) like English does to show an action is happening right now. The simple present tense verb sover covers both "sleeps" and "is sleeping". You just use the context of the sentence to know which one sounds best in English!