? EXPERIMENT (Countable)
An experiment is a single, specific test or procedure designed to discover something.

?? CORRECT: We carried out an experiment.
?? CORRECT: A scientist performed an experiment on mice.

?? Highlight: You can have one experiment or many experiments. It's countable!

?? RESEARCH (Uncountable)
Research is the entire process of studying a subject to discover new information. It often involves many experiments.

?? CORRECT: We carried out research.
?? CORRECT: We carried out some research.
?? CORRECT: A scientist performed research on mice.

?? Highlight: Never use "a" with research. Think of it like "water" or "information"—you can't have "a water," you have "some water." You do research, not a research.

@Vocab @Pdf