I was told that these three phases have the same meanings, but I want to know if there are any differences between them:
- sort of
- kind of
Sort of X and kind of X can be analysed as simple Noun Phrases in examples like this:
Here we have the nouns sort and kind taking preposition phrases: of X, where X is a noun. The meaning in each case is almost exactly the same. It just indicates that the subject of the sentence is a variety of X, a type of X. In the examples above, a type of toy, or a type of instrument. Sort of is less useful with biological things:
Somewhat, however, is not a noun and cannot enter into this type of construction:
*It's a somewhat toy. (wrong)
*It's a somewhat of toy. (wrong)
In terms of this type of usage, sort of might be considered informal. Kind of on the other hand would be fine in most types of speech and writing.
However, sort of and kind of although they look like Noun Phrases, have taken on the status of individual degree adverbs when used with adjectives or verbs.
Here we see them modifying the adjective green. There is no reason here to consider sort or kind as nouns any more. The phrases only make sense when considered as a chunk: sort of/ kind of. Because each chunk is one adverb but two words, some writers call them complex adverbs.
Both of these adverbs sort of and kind of have a meaning similar to approximately. So in the sentence it was kind of green, it means that the colour of the alien was approximately green, something similar to green.
Somewhat, according to the analysis given by The Cambridge Grammar of the English Language, however, has a slightly different meaning. They refer to somewhat as indicating a "moderate" degree. Somewhat therefore, means something in between a little and very:
So in the example above the degree of embarrassment was appreciable, but not great.
Usually there is not much to choose between sort of, kind of and somewhat. In the examples given above, it would make little difference which one was used. Despite agreeing with the difference in meaning ascribed by CaGEL, I have struggled to find an example where the difference between sort of & kind of, or somewhat would be very clear when used with adjectives. The biggest difference, it seems to me, is actually in the usage not the meaning. The adverbs sort of and kind of are both definitely quite informal. Somewhat, on the other hand, would nearly always be regarded as formal and occasionally as quite pompous.
Interestingly, all three adverbs have similar patterns in terms of the way that stress affects their interpretations. When the stress is on the adverb, the speaker gives emphasis to the idea of not to a great degree, they minimise the effect of the adjective:
On the other hand if they stress the adjective then the interpretation of the adverbs is that the effect was appreciable:
The three adverbs above can also be used to modify verbs as well as adjectives. In terms of formality, they retain the same differences in formality as described above. The big difference here, is that sort of and kind of usually appear in post-auxiliary position, in the same place we would expect adverbs such as always or never. Somewhat, in contrast, tends to appear after the verb.
With verbs it is easier to show the difference in meaning between somewhat and the other adverbs. For example, the verb promise doesn't readily come in degrees! It's therefore difficult to use somewhat with the verb promise. You can't promise slightly or a lot. However, you can do something similar to promising without actually actually promising. You can give a strong assurance you can imply that you guarantee and so forth. Therefore we see the following contrast: