Following sentences are grammatically incorrect. I can’t find the error.
1- Residents complained that officials always give an excuse that the pipelines were old and the colony would be getting proper water supply, once they were replaced.
2- The unexpected strength of vehicles especially four wheelers had caused the traffic jam and the traffic was moving at a snail’s pace.
The most noticeable errors are underlined. In addition, ask yourself whether the colony are being replaced, or the pipes?
1- Residents complained that officials always give an excuse that the pipelines were old and the colony would be getting proper water supply, once they were replaced.
2- The unexpected strength of vehicles especially four wheelers had caused the traffic jam and the traffic was moving at a snail’s pace.