The gear may not be able to be engaged due to several reasons. It could be due to a mechanical issue such as a worn-out clutch or gearbox, which prevents the gear from properly engaging. It could also be due to a lack of hydraulic pressure in the transmission system, preventing the gear from fully engaging. Additionally, the gear may not be able to engage if there is a problem with the gear shift linkage or if the gear synchronizer is worn out. It is important to have the issue diagnosed and repaired by a qualified mechanic to ensure safe and proper operation of the vehicle. **

To know which gear is engaged in a manual transmission vehicle, you can look at the position of the gear shifter. The gear shifter will be in a specific position depending on which gear is engaged, such as first gear being towards the driver and fifth gear being away from the driver. Additionally, you can also feel the resistance when trying to shift into a gear, which can help you determine if the gear is engaged or not. Lastly, you can look at the dashboard display or indicator lights, if your vehicle is equipped with them, to see which gear is currently engaged. **

No, it is not recommended to keep the gear engaged while sailing. When sailing, it is best to have the engine in neutral to prevent unnecessary wear and tear on the transmission and engine. Additionally, having the gear engaged while sailing can make it more difficult to maneuver and control the boat effectively. It is important to follow proper sailing techniques and procedures to ensure a safe and enjoyable experience on the water. **

The gear that should be engaged in the car depends on the driving situation. If the car is at a complete stop, the gear should be in neutral or park. When starting to move, the gear should be shifted to first gear or drive for automatic transmission. For higher speeds, the gear should be shifted to higher gears such as second, third, or fourth, depending on the speed and road conditions. It is important to always follow the specific gear shifting instructions provided in the car's manual. **

The first gear should be engaged when starting the car from a complete stop, such as when pulling away from a stop sign or traffic light. It provides the most power and torque to get the car moving from a standstill. Once the car is in motion, the driver can then shift to higher gears as the speed increases. **

The handbrake should be used when parking on a slope or incline to prevent the car from rolling. Engaging the gear (usually first or reverse) is also recommended as an additional safety measure, especially in manual transmission cars. Using both the handbrake and engaging the gear provides extra security and ensures the car stays in place while parked. **

To engage the first gear without using the clutch, the vehicle needs to be at a complete stop. Then, the driver can shift the gear lever into first gear while gently applying pressure on the gas pedal. As the vehicle starts to move forward, the transmission will engage the first gear without the need for the clutch. This technique is known as "rev-matching" and requires precise timing and coordination to avoid damaging the transmission. It should be used sparingly and only in emergency situations. **

If the gear in the car transmission is not properly engaged, it can result in difficulty shifting gears, grinding noises, or the car not moving when the transmission is in gear. This could be caused by issues such as low transmission fluid, a worn clutch, or a malfunctioning shift linkage. It is important to have the transmission inspected and repaired by a qualified mechanic to prevent further damage to the vehicle. **