Adjectives with a built-in very: trắng tinh, nặng trịch (no rất)

Some adjectives have a partner syllable that turns them up to the top: trắng tinh (pure white), nóng hổi (piping hot), nặng trịch (really heavy), mới tinh (brand new). The partner has no meaning you need on its own. It works like "brand" in "brand new" or "pitch" in "pitch dark".

Each partner fits only its own adjective, so they're learnt pair by pair. A few useful ones: tối thui (pitch dark), chua lè (really sour), ngọt lịm (sweet through and through), sạch bong (spotless), thẳng tắp (dead straight). Some pairs differ by region: Saigon says tối thui where Hà Nội says tối om.

Because the partner already means "completely", rất, lắm and quá don't go with these pairs. Say Cái áo này trắng tinh, not rất trắng tinh.

They're everyday and vivid, typical when you describe something you can see, touch or taste, and they're common in stories too. Use them about things more than people: some pairs about a person's looks can sound blunt.

If you don't know the pair, the plain adjective with rất or quá is always safe: rất nặng, nặng quá.