I stutter in every language I speak. Fewer blocks or repetitions occur when I speak my native language however, because I have a richer vocabulary and can easily rearrange words in a sentence or find a synoym if I feel a block is coming. It's still hard to introduce myself sometimes unfortunately, as I cannot change my name and my name also happens to be one of the words on which I stutter more often. Unrelated, but I've noticed that if when I read I arbitrarily change the stress of a word and emphasise the wrong syllable, I usually overcome the block. It produces an effect similar to reading with a metronome.