The word "whenever" is a subordinating conjuction that goes before a dependent clause. It’s very similar to "when." We use "whenever" to mean "at any time" or "at the precise time." You can also use "whenever" as a single word in a response to a question.
examples
1. Her mother buys ice cream for her whenever they go to the beach.
2. Whenever Barney goes golfing, he brings his cell phone out onto the golf course.
3. People are amazed by the beauty of the Taj Mahal whenever they see it up close.
4. Whenever it’s really cold outside, he wears a hat, a scarf, boots, mittens, and a heavy coat.
5. Maria gets very embarassed whenever she makes a mistake.
6. Whenever she’s handling bees, she’s very careful not to disturb them too much.
7. Oxana calls her friends for help whenever she has trouble understanding her English homework.