Learn Spanish (Latin America): Prenso el queso hasta la tarde. - I do not press the cheese until the afternoon.

This is a common feature in many parts of Latin America (especially Mexico and Central America). When you use hasta with a time expression in an affirmative sentence, it implies that the action doesn't start until that time. You don't need to add no to get the "not until" meaning; the structure does the work for you.

Would it be wrong to say No prenso el queso hasta la tarde?

It wouldn't be wrong at all! Adding no makes it standard Spanish everywhere. However, you need to recognize this affirmative version because native speakers in Latin America use it constantly in everyday conversation.

How do people know if I mean "I press the cheese up until the afternoon" instead of "not until"?

Context is your best friend here. However, to make it completely unambiguous that an action is continuous and stops at that time, Spanish speakers often use a duration phrase or the progressive tense, like Estoy prensando el queso hasta la tarde (I am pressing the cheese until the afternoon).

What is the infinitive of prenso, and can I use it to mean pressing a button?