1. First conditional: "If I still haven't heard back and it's urgent, I'd probably try another way..." uses a first conditional structure (if + present perfect, would + base verb) to talk about a possible future situation and the response to it.
2. Present perfect tense: "I still haven't heard back" uses the present perfect to describe a situation that started in the past and continues to the present.
3. Gerund as object: "giving them a call" and "using a different messaging app" both use gerunds as the object of the phrase, showing a natural way to talk about actions.
4. Emphatic structure: "nothing beats face-to-face communication" is a strong, emphatic way to express preference, using the present simple for general truth.