M.M.
Two of my three kids have the same issue. Chewables usually work well, and now several meds come in the strips that melt on their tongue. My kids have no trouble with either. When they were younger, if it HAD to be liquid, I'd wait until they were asleep, turn their heads to the side and use a dropper. Put only a drop or two on the inside of the cheek, towards the back of the mouth. Be sure it's on the cheek so they don't gag or choke. The sensation of the liquid moving towards their throat made them swallow. It's a slow process to get the entire dose down, but it sure is better than the tears, vomiting, and major struggle of trying to coerce them.