But they are most likely to drop a weak syllable that begins a word. But if you point out a lion, where the second syllable is stressed, they'll say it correctly. Allophonic differences - sometimes, we pronounce sounds differently at the ends of words than at the beginnings of words. That is, we have different variants of the same sound that occur in different contexts. This isn't the case for all sounds, though, which would suggest that some words may be more difficult than others.
Some sounds are more common in initial position, whereas others are more common in final position.
So if you hear that sound, you know it can't be the start of a new word. In addition to items like this, which can only occur in certain positions, there are sounds which primarily occur in certain positions. They played people multisyllabic nonsense words, and had them listen for real words that were embedded in them. But, a lot of these types of cues that we use are ones that require prior learning. An infant just learning the language woudln't be able to use knowledge about what really was a word in the language.