Can 'I would say' always replace 'I think'?
There is a question about 'I guess' and one answer is comparing 'I guess', and 'I would say'.
I would say characterizes what follows as a personal opinion or judgment: From what I know of him I would say he is coming.
I guess characterizes what follows as a conjecture or inference: Well, if he were coming he'd be here by now, so I guess he's not coming.
My question is I am bored of 'I think' every time I wanna tell my idea, so can I use 'I would say' instead of it? As an non-native English speaker, I feel 'I would say' is more aggressive than 'I think', is that true?
Solution 1:
They're not always interchangeable.
In addition to the point made by Sven Yargs, the two expressions also base themselves on different evidence in some cases:
If your statement is meant to indicate that you are just freely conjecturing and that you are not sure whether your conjecturing is correct or not, use I think:
— Where is your brother?
— Um, not sure… I think he's in the garden.
If your intention is rather to indicate that you are weighing the possible options against each other and choosing the one that seems most likely to you based on what information you have available, you can use I’d say or I think quite interchangeably:
— Where's your brother?
— Um, not sure… he said he was going out to get some weed killer, pick some things up at dad’s place, and then get rid of some of that hemlock out the back, but that was a while ago, so he should be back. Yeah, I'd say he's probably in the garden now.
I’d say in this scenario indicates that you're making your own reasonable assumption with some kind of logical basis, rather than just saying whatever you happen to think of first.
(Naturally, they are not interchangeable in many other contexts as well: “I think about this often” cannot be replaced by “I’d say about this often”, which doesn’t make any sense at all; and “I think, therefore I am” should only be changed to “I’d say, therefore I am” if you wish to be hunted down and brutally murdered by Descartes’ ghost.)
Solution 2:
"I would say" almost always expresses tentativeness about what follows, either due to lack of definite knowledge or a desire to avoid offending/dominating/etc.
"I think" is a more positive statement, one that definitely expresses your own personal perspective, while allowing for other points of view.
Neither makes a claim of absolute, objective truth about what follows, but "I think" comes closer.