The adjective here, critical, is really interesting, it can be used in a lot of different ways. One meaning is when someone is quick to judge or find fault in something. Parents who are too critical can make their children anxious. Critical thinking is a skill I wish we’d teach more of in schools. That’s when you learn how to judge the truth or merit of an idea, critical thinking. A different meaning, which is the one used in this news story, indicates a threatening or grave outcome. A critical shortage of lifeguards. There aren’t enough lifeguards, so swimmers face potential danger. You might also hear the phrase ‘critical acclaim’. This means critics have praised the work. For example, a movie, play, or restaurant can have critical acclaim. Critics are people who work for an organization, like a newspaper, who judge how good something is. For example, a restaurant critic would work for a newspaper, visit various restaurants throughout the city to rate them and write articles about certain dishes, and so on. A critic. There’s no substitute for safety. And the lifeguards are a part of the safety chain. If there’s no substitute for something, that means there’s no backup, no replacement, no stand-in. Nothing else that works to the same goal. Either we’re practicing safety or we’re not. I often hear this usage of substitute as a motivator: There’s no substitute for hardwork. This means there’s no other way to success. You have to put in the time and hard work. There’s no substitute for experience. There’s no substitute for safety. And the lifeguards are a part of the safety chain. Safety chain. He’s using the image of a chain metaphorically. Each link or piece of a chain holds onto the other. Lifeguards are part of the chain–along with EMS workers, police, other medical professionals, and even the general public. We all need to make smart decisions when it comes to swimming. You’ll hear the word “chain” used in other ways too: the food chain the supply chain They all reference several steps or parts that make up the flow of a process. There’s no substitute for safety. And the lifeguards are a part of the safety chain. Areas are not able to hire and certify lifeguards fast enough–just as more Americans are flocking to water-front destinations. Hire and certify. Hire is to be offered a job for pay. The process of someone becoming employed by you. If you hire someone, they become staff. Certified includes all the training, licensing, and approval you need to do a specialized job or task. I’m pretty good at excel, but I haven’t been certified. Some jobs might require some certifications. For example, to work at the daycare, she needed to be certified in CPR. So, she took a class to become CPR certified: watched videos, took tests, and demonstrated skills on a dummy and so on. She’ll need to renew her certification every two years. Areas are not able to hire and certify lifeguards fast enough–just as more Americans are flocking to water-front destinations. Flocking. I love this use of “flock!” It’s a verb or noun we typically associate with birds. A group of birds is a flock. And “flocking” describes their movement as a group. My neighbor throws peanuts on the street and the birds flock to it. So, if people are “flocking to water-front destinations,” that means large numbers are going there. Everyone wants it, kind of like hungry birds for peanuts. Areas are not able to hire and certify lifeguards fast enough–just as more Americans are flocking to water-front destinations. No fun in the sun at this pool in Lackawanna State Park in Pennsylvania. It closed due to staffing shortages. There’s our noun again–shortages. This time it’s “staffing shortages.” Not enough staff, not enough workers to safely open. No fun in the sun at this pool in Lackawanna State Park in Pennsylvania. It closed due to staffing shortages. In Ohio, notices like these on Facebook turning away eager pool-goers. What’s the Facebook notice doing?