Yes it is. Example - sometimes people are "tongue-tied" - they know what they want to say, but can't remember the word for that.

Is that really a "thought" though, or is it just a feeling/intuition/primordial emotional concept up until the point that it can be congealed into words?

What's the difference between "feeling/intuition/primordial emotional concept" and thought for those who aren't dualists?

If you have some form of aphasia it may be hard for you to find the words you need to say, but you can still choose and reason about what you're thinking about. You're able to conceptualise, you just can't put the right words to the right concepts. It's definitely far more than a feeling or intuition.

As always - everything depends on definitions :)

In my opinion feelings(probably) and concepts(for sure) are subsets of thoughts. But I'm not native English speaker, and this is subjective in my language too, so we can argue about that.

This is a huge debate: http://en.wikipedia.org/wiki/Linguistic_relativity I'd probably agree with the weak version that language does influence thought, although it does not control it totally.

If you're asking in terms of all-or-nothing, then I'd have to say yes. Animals think without words.